Patent Description:
Mechanical joint pipe connections are a common method for attaching a pipe length to a piping element such as a valve, a coupling, or a fitting, such as a tee or elbow, or another pipe. The mechanical joint pipe connection can comprise a female socket, a gland, a gasket, and a pipe length. The piping element commonly defines a female socket configured to receive a plain end of the pipe length and a gasket. A gland is commonly provided which slips over the plain end of the pipe length, and the gland is tightened by a series of bolts which draw the gland towards the female socket, thereby compressing the gasket. Compression of the gasket causes the gasket to engage an outer surface of the plain end of the pipe length, thereby forming a seal between the pipe length and the element.

Mechanical joint pipe connections are popular because mechanical joint pipe connections function with the plain end of the pipe length, unlike groove connections or flanged connections that require preparation of the plain end of the pipe length. The ability to function with the plain end allows for the pipe length to be cut to size in a field installation without requiring the time and field equipment necessary to weld a flange to the plain end or to cut a new groove in the plain end. Mechanical joint pipe connections can be assembled quickly with common hand tools such as a wrench or ratchet.

However, typical mechanical joint pipe connections do not provide for a positive retention mechanism other than friction of the gasket acting on the plain end of the length. The lack of a positive retention mechanism can compromise the seal or lead to the plain end pulling out of the female socket when the connection is subjected to high tension force or effects such as water hammer. Some mechanical joint pipe connections can incorporate a joint restraint mechanism configured to mechanically engage the plain end of the pipe; however, existing joint restraint mechanisms can exert high stresses upon the plain end of the pipe length which can lead to deformation, creep, and cracking of the plain end of the pipe length during installation or operation. Deformation, creep, and cracking can lead to failure of the seal or failure of the pipe length itself which can result in leaks or environmental contamination.

<CIT> discloses a pipe connecting system using rotatable wedges.

<CIT> discloses a retainer ring for coupling together water supply pipes or the like.

<CIT> discloses a pressing wheel for cast-iron pipe with horizontally pushing spike that is separation prevention.

Various aspects of the invention are defined in the appended claims.

The features and components of the following figures are illustrated to emphasize the general principles of the present disclosure. The drawings are not necessarily drawn to scale. Corresponding features and components throughout the figures may be designated by matching reference characters for the sake of consistency and clarity.

The present disclosure can be understood more readily by reference to the following detailed description, examples, drawings, and claims, and the previous and following description. However, before the present devices, systems, and/or methods are disclosed and described, it is to be understood that this disclosure is not limited to the specific devices, systems, and/or methods disclosed unless otherwise specified, and, as such, can, of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing particular aspects only and is not intended to be limiting.

The following description is provided as an enabling teaching of the present devices, systems, and/or methods in its best, currently known aspect. To this end, those skilled in the relevant art will recognize and appreciate that many changes within the scope of the claims can be made to the various aspects of the present devices, systems, and/or methods described herein, while still obtaining the beneficial results of the present disclosure.

As used throughout, the singular forms "a," "an" and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to "an element" can include two or more such elements unless the context indicates otherwise.

For purposes of the current disclosure, a material property or dimension measuring about X or substantially X on a particular measurement scale measures within a range between X plus an industry-standard upper tolerance for the specified measurement and X minus an industry-standard lower tolerance for the specified measurement. Because tolerances can vary between different materials, processes and between different models, the tolerance for a particular measurement of a particular component can fall within a range of tolerances.

As used herein, the terms "optional" or "optionally" mean that the subsequently described event or circumstance can or cannot occur, and that the description includes instances where said event or circumstance occurs and instances where it does not.

The word "or" as used herein means any one member of a particular list and also includes any combination of members of that list. Further, one should note that conditional language, such as, among others, "can," "could," "might," or "may," unless specifically stated otherwise, or otherwise understood within the context as used, is generally intended to convey that certain aspects include, while other aspects do not include, certain features, elements and/or steps. Thus, such conditional language is not generally intended to imply that features, elements and/or steps are in any way required for one or more particular aspects or that one or more particular aspects necessarily include logic for deciding, with or without user input or prompting, whether these features, elements and/or steps are included or are to be performed in any particular aspect.

Disclosed is a gland and associated methods, systems, devices, and various apparatus. The gland comprises an annular ring and a joint restraint assembly. It would be understood by one of skill in the art that the disclosed gland is described in but a few exemplary embodiments among many. No particular terminology or description should be considered limiting on the disclosure or the scope of any claims issuing therefrom.

<FIG> shows a perspective view of a piping element assembly <NUM>. The pipe element assembly <NUM> can comprise a piping element <NUM>, a first gland 124a, a second gland 124b, a first pipe length 102a, and a second pipe length 102b. The pipe lengths 102a,b are shown as relatively short lengths for exemplary purposes, and each of the pipe lengths 102a,b can be significantly longer than shown. In application, the pipe lengths 102a,b can be comprised by a piping system or a piping infrastructure, such as a municipal water infrastructure or any other piping system or piping infrastructure.

In the present aspect, the piping element <NUM> can be a valve <NUM>, such as a gate valve, a ball valve, a butterfly valve, a globe valve, or any other suitable type of valve. In other aspects, the piping element <NUM> can be a coupling configured to mechanically couple and seal the first pipe length 102a with the second pipe length 102b in fluid communication. In other aspects, the piping element <NUM> can be a pipe fitting, such as a tee, an elbow, a reducer, a wye, a shaped fitting, or any other suitable type of pipe fitting. In other aspects, the piping element <NUM> can be equipment such as a fire hydrant. In such aspects, the piping element assembly <NUM> may not comprise the second gland 124b and the second pipe length 102b, and the fire hydrant can define an end of a leg of the municipal water infrastructure.

The piping element <NUM> can comprise a first element flange 122a and a second element flange 122b. The first element flange 122a can be disposed opposite from the second element flange 122b. The first element flange 122a, the first gland 124a, and the first pipe length 102a can define a first mechanical joint 120a. The second element flange 122b, the second gland 124b, and the second pipe length 102b can define a second mechanical joint 120b. The first mechanical joint 120a can be configured to mechanically couple and seal the first pipe length 102a to the piping element <NUM>, and the second mechanical joint 120b can be configured to mechanically couple and seal the second pipe length 102b to the piping element <NUM>.

The first gland 124a can be coupled to the first element flange 122a by a first plurality of fasteners 126a. In the present aspect, the first plurality of fasteners 126a can be T-bolts; however in other aspects, the fasteners 126a can be bolts, studs, or any other suitable type of fasteners. Each of the first plurality of fasteners 126a can engage, a flange slot 128a, a flange hole 130a, or similar flange slots 128a or flange holes 130a defined by the first element flange 122a. The first plurality of fasteners 126a can be configured to draw the first gland 124a towards the first element flange 122a.

The first gland 124a can comprise a first annular ring 125a and a first plurality of joint restraint assemblies 134a. In the present aspect, the first gland 124a can comprise six joint restraint assemblies 134a; however, the quantity of joint restraint assemblies 134a should not be viewed as limiting, and the first gland 124a can comprise greater or fewer joint restraint assemblies 134a in other aspects. In the present aspect, the joint restraint assemblies 134a can be equally spaced about a circumference of the first annular ring 125a; however, this distribution should not be viewed as limiting, and the joint restraint assemblies 134a can be distributed in any suitable arrangement.

The first gland 124a is shown in <FIG> in an activated configuration. In the activated configuration, each of the joint restraint assemblies 134a of the first gland 124a can engage the first pipe length 102a in order to prevent removal of the first pipe length 102a from the piping element <NUM>.

The second gland 124b can be coupled to the second element flange 122b by a second plurality of fasteners 126b. In the present aspect, the second plurality of fasteners 126b can be T-bolts; however, in other aspects, the fasteners 126b can be bolts, studs, or any other suitable type of fasteners. Each of the second plurality of fasteners 126b can engage a flange slot 128b, a flange hole 130b, or similar flange slots 128b or flange holes 130b defined by the second element flange 122b. The second plurality of fasteners 126b can be configured to draw the second gland 124b towards the second element flange 122b.

The second gland 124b can comprise a second annular ring 125b and a second plurality of joint restraint assemblies 134b. In the present aspect, the second gland 124b can be similar in structure to the first gland 124a. The second gland 124b can comprise six joint restraint assemblies 134b; however, the quantity of joint restraint assemblies 134b should not be viewed as limiting, and the second gland 124b can comprise greater or fewer joint restraint assemblies 134b in other aspects. In the present aspect, the joint restraint assemblies 134b can be equally spaced about a circumference of the second annular ring 125b; however, this distribution should not be viewed as limiting, and the joint restraint assemblies 134b can be distributed in any suitable arrangement.

The second gland 124b is shown in <FIG> in a deactivated configuration in which each of the joint restraint assemblies 134b of the second gland 124b is prevented from engaging the second pipe length 102b by a deactivation mechanism <NUM>. In the present aspect, the deactivation mechanism <NUM> can be an o-ring, rubber band, bungee cord, or similar elastic member, and is discussed in further detail below.

<FIG> is a cross sectional view of the pipe element assembly <NUM> of <FIG> taken across line <NUM>-<NUM> shown in <FIG>. The piping element <NUM> can define a first socket 222a sized to accept the piping element <NUM> within the first element flange 122a. The piping element <NUM> can also define a second socket 222b sized to accept the piping element <NUM> within the second element flange 122b. The piping element can define an element bore <NUM> extending through the piping element <NUM> from the first socket 222a to the second socket 222b. The element bore <NUM> can be representative of any piping element <NUM>, such as a coupling or pipe fitting. In aspects in which the piping element <NUM> is an angled fitting such as an elbow fitting, the element bore <NUM> can be curved or angled. In aspects in which the piping element <NUM> is a fitting such as a tee or a wye, the element bore <NUM> can be forked or defined by multiple bores intersecting each other. In the present aspect, the element bore <NUM> can be substantially cylindrical, and the element bore <NUM> can define an element bore axis <NUM> therethrough.

The first annular ring 125a of the first gland 124a can define a first gland bore 206a. The first gland bore 206a can define a first gland axis 207a which can be substantially coincident with the element bore axis <NUM> such that the first gland bore 206a and the element bore <NUM> can be coaxial. The first pipe length 102a can extend through the first gland bore 206a into the first socket 222a. The first pipe length 102a can be substantially coaxial with the first gland axis 207a and the element bore axis <NUM>.

The second annular ring 125b of the second gland 124b can define a second gland bore 206b. The second gland bore 206b can define a second gland axis 207b which can be substantially coincident with the element bore axis <NUM> and the first gland axis 207a such that the first gland bore 206a, the second gland bore 206b, and the element bore <NUM> can be substantially coaxial. The second pipe length 102b can extend through the second gland bore 206b into the second socket 222b. The second pipe length 102b can be substantially coaxial with the first gland axis 207a, the second gland axis 207b, and the element bore axis <NUM>.

The mechanical joint 120a of the pipe element assembly <NUM> can further comprise a first gasket 228a, and the mechanical joint 120b of the pipe element assembly <NUM> can further comprise a second gasket 228b. The first gasket 228a can be disposed axially between the piping element <NUM> and the first gland 124a within the first socket 222a. The first gasket 228a can be configured to seal against a first outer pipe surface 204a defined by the first pipe length 102a. The second gasket 228b can be disposed axially between the piping element <NUM> and the second gland 124b within the second socket 222b. The second gasket 228b can be configured to seal against a second outer pipe surface 204b defined by the second pipe length 102b.

As previously described, the first gland 124a is shown in the activated configuration wherein a first gripper 232a of each of the joint restraint assemblies 134a can be positioned to engage the first outer pipe surface 204a. In the present aspect, the first grippers 232a are in a final engagement position which prevents any withdrawal of the first pipe length 102a from the first socket 222a. The final engagement position is shown and further described below with respect to <FIG>.

The second gland 124b is shown in the deactivated configuration wherein a second gripper 232b of each of the joint restraint assemblies 134b can be disengaged from the second outer pipe surface 204b by the deactivation mechanism <NUM>. In the present aspect, the second grippers 232b are shown in a disengaged position in which the second pipe length 102b can freely be inserted, withdrawn, or completely removed from the second socket 222b. The disengaged position is shown and further described below with respect to <FIG>.

<FIG> is a detail view of the second mechanical joint 120b of the pipe element assembly <NUM> taken from Detail <NUM> shown in <FIG>. The second mechanical joint 120b can be representative of either of the aspects of the mechanical joints 120a,b as shown in <FIG>, and components of the pipe element assembly <NUM> are referred to in generality hereafter. For example, the second mechanical joint 120b is simply referred to as the mechanical joint <NUM> below.

As previously described, the gland <NUM> in the present aspect can be placed in the deactivated configuration, and the gripper <NUM> can thereby be placed in the disengaged position which allows the pipe length <NUM> to freely move into the socket <NUM> in an insertion direction <NUM> or outwards from the socket <NUM> in a withdrawal direction <NUM>. The piping element <NUM> can define a pipe shoulder <NUM> between the socket <NUM> and the element bore <NUM>. The pipe shoulder <NUM> can be configured to provide a positive stop for a plain end <NUM> of the pipe length <NUM> which can limit a depth of insertion of the pipe length <NUM> into the socket <NUM>.

The pipe element <NUM> can define a gasket groove <NUM>. The gasket groove <NUM> can define a taper, and the gasket groove <NUM> can define a substantially triangular or trapezoidal profile. The gasket groove <NUM> can be shaped to receive the gasket <NUM>. The annular ring <NUM> of the gland <NUM> can be configured to engage the gasket <NUM>. The annular ring <NUM> can define an engagement bevel <NUM>. The engagement bevel <NUM> can be substantially frustoconical in shape, and the engagement bevel <NUM> can face radially inward with respect to the bore axis <NUM> and the gland axis <NUM> (both shown in <FIG>). Tightening of the fasteners <NUM> can draw the gland <NUM> towards the element flange <NUM> of the pipe element <NUM>, thereby compressing the gasket <NUM> in the gasket groove <NUM>. The engagement bevel <NUM> and the taper of the gasket groove <NUM> can cooperate to compress and deform the gasket <NUM> radially inward with respect to the bore axis <NUM> and gland axis <NUM>. Compression and deformation of the gasket <NUM> can press an inner gasket surface <NUM> of the gasket <NUM> against the outer pipe surface <NUM>, thereby energizing the gasket <NUM> and creating a seal between the gasket <NUM> and the outer pipe surface <NUM>. With the gasket <NUM> compressed, friction between the inner gasket surface <NUM> and the outer pipe surface <NUM> can resist movement of the pipe length <NUM> in both the insertion direction <NUM> and the withdrawal direction <NUM>.

The socket <NUM> can taper radially outward as the socket <NUM> extends axially away from the gasket groove <NUM> and towards the pipe shoulder <NUM>. The gland bore <NUM> can taper radially outward as the gland bore <NUM> extends axially away from the engagement bevel <NUM>. The respective tapers of the socket <NUM> and the gland bore <NUM> can provide clearance on either side of the gasket <NUM> to allow the pipe length <NUM> to tilt and demonstrate limited angular deflection relative to the bore axis <NUM> and gland axis <NUM> (shown in <FIG>). In the present aspect, the pipe length <NUM> can demonstrate angular deflection of up to <NUM> degrees relative to the bore axis <NUM>; however, this value should not be viewed as limiting. The socket <NUM> and the gland <NUM> can be sized and shaped to allow for larger or smaller angular deflection of the pipe length <NUM>.

In the present aspect, the angular deflection can be limited by the size and geometry of the socket <NUM>, and the gland <NUM>; however, the joint restraint assembly <NUM> can tolerate larger values of angular deflection. The taper of the gland bore <NUM> can also aid in slipping the gland <NUM> over the plain end <NUM> of the pipe length <NUM> during installation. The taper and sizing of the gland bore <NUM> can be configured to provide clearance for the gripper <NUM> to clear the outer pipe surface <NUM> in the deactivated configuration.

Each joint restraint assembly <NUM> can comprise a restraint base <NUM>, a spring clip <NUM>, and a one of the grippers <NUM>. The joint restraint assembly <NUM> can be assembled on the restraint base <NUM>. In the present aspect, the restraint base <NUM> can be integrally defined by the gland <NUM>; however in other aspects, the restraint base <NUM> can be a separate component which can be attached or fastened to the annular ring <NUM> of the gland <NUM>. In some aspects, a position of the restraint base <NUM> on the annular ring <NUM> can be adjusted, such as by moving the restraint base <NUM> radially inward or outward relative to the gland axis <NUM> (shown in <FIG>). Such adjustment can allow the gland <NUM> to be configured for different sizes of pipe lengths <NUM> having different outer diameters. In some aspects, the restraint bases <NUM> can also be adjusted on the annular ring <NUM> axially relative to the gland axis <NUM>. The restraint base <NUM> can define a restraint pocket <NUM> and a restraint pivot <NUM>. The gripper <NUM> and the spring clip <NUM> can be disposed within the restraint pocket <NUM>.

The gripper <NUM> can rotate about the restraint pivot <NUM> such that the engagement end <NUM> of the gripper <NUM> can be drawn into and out of contact with the outer pipe surface <NUM>. The gripper <NUM> can define a gripper bearing surface <NUM>, and the restraint pivot <NUM> can define a restraint bearing surface <NUM>. The gripper bearing surface <NUM> can be shaped complimentary to the restraint bearing surface <NUM>, and the gripper bearing surface <NUM> can be in facing contact with the restraint bearing surface <NUM>. The gripper bearing surface <NUM> can be configured to slide around the restraint bearing surface <NUM> as the gripper <NUM> rotates about the restraint pivot <NUM>.

The gripper <NUM> can define an engagement end <NUM> and a lever end <NUM>. The engagement end <NUM> can be disposed opposite from the lever end <NUM> with the gripper bearing surface <NUM> defined between the engagement end <NUM> and the lever end <NUM>. The engagement end <NUM> can extend into the gland bore <NUM> towards the gland axis <NUM> (shown in <FIG>). The spring clip <NUM> can bias the gripper <NUM> to rotate about the restraint pivot <NUM> towards engagement with outer pipe surface <NUM>. Specifically, an engagement leg <NUM> of the spring clip <NUM> can press on the engagement end <NUM> of the gripper <NUM>. A retention tab <NUM> of the spring clip <NUM> can engage a locator bore <NUM> defined by the restraint base <NUM>. The engagement of the retention tab <NUM> with the locator bore <NUM> can position and secure the spring clip <NUM> within the restraint pocket <NUM>, and the spring clip <NUM> can thereby maintain the engagement between the gripper <NUM> and the restraint pivot <NUM>.

In the deactivated configuration, the deactivation mechanism <NUM> can prevent rotation of the gripper <NUM> towards engagement with the outer pipe surface <NUM>. In the present aspect, the deactivation mechanism <NUM> can be elastic, and tension of the deactivation mechanism <NUM> can overpower the spring clips <NUM>. The deactivation mechanism <NUM> can pull on the lever end <NUM> of the gripper <NUM> to position the gripper <NUM> in the disengaged position wherein the gripper <NUM> is out of contact with the outer pipe surface <NUM>. The deactivation mechanism <NUM> can comprise a stretchable material such as an O-ring, a rubber band, a bungee cord, or any other suitable elastically stretchable material.

In the present aspect, the deactivation mechanism <NUM> can simultaneously deactivate all of the joint restraint assemblies <NUM> of the gland <NUM>. Removing the deactivation mechanism <NUM> from the gripper <NUM> can activate each joint restraint assembly <NUM>, as shown in <FIG>. The deactivation mechanism <NUM> can be individually slipped off of the lever end <NUM> of each gripper <NUM> to individually activate the respective joint restraint assembly <NUM>, or the deactivation mechanism <NUM> can be cut, such as with scissors, which can simultaneously activate all of the joint restraint assemblies <NUM> of the gland <NUM>. In some aspects, the lever end <NUM> can define a deactivation feature (not shown) such as an extension, a hook, or a pin configured to engage the deactivation mechanism <NUM>. The deactivation feature can be configured to prevent pinching of the deactivation mechanism <NUM> between the lever end <NUM> and the restraint base <NUM> which can bind the gripper <NUM> under some conditions.

<FIG> is a detail view of the mechanical joint <NUM> of the pipe element assembly <NUM> taken from Detail <NUM> shown in <FIG> with the gripper <NUM> shown in an initial engagement position. The gripper <NUM> can rotate about the restraint pivot <NUM> under the bias of the spring clip <NUM>. The restraint bearing surface <NUM> can define a pivot radius of curvature R<NUM> and a pivot center axis P<NUM>. The pivot center axis P<NUM> can be perpendicular to both an axial direction and a radial direction with respect to the gland axis <NUM> (shown in <FIG>). The complimentary shapes of the gripper bearing surface <NUM> and the restraint bearing surface <NUM> allows the gripper <NUM> to rotate around the pivot center axis P<NUM> while maintaining facing contact between the gripper bearing surface <NUM> and the restraint bearing surface <NUM>.

The spring clip <NUM> biases the gripper <NUM> to rotate about the pivot center axis P<NUM> in an engagement direction <NUM> (counter-clockwise in the aspect shown). The deactivation mechanism <NUM> (shown in <FIG>) biases the gripper <NUM> to rotate in a disengagement direction <NUM> (clockwise in the aspect shown). Once the deactivation mechanism <NUM> (shown in <FIG>) has been removed and the joint restraint assembly <NUM> is placed in the activated configuration, the gripper <NUM> can rotate in the engagement direction <NUM> such that the engagement end <NUM> engages the outer pipe surface <NUM>.

The gripper <NUM> can define a leading edge <NUM> and a trailing edge <NUM> at opposite sides of the engagement end <NUM>. The leading edge <NUM> and the trailing edge <NUM> are named with respect to rotation in the engagement direction <NUM>. The gripper <NUM> can comprise a plurality of gripping protuberances <NUM> disposed on the engagement end <NUM>. Each gripping protuberance <NUM> can extend outwards from the engagement end <NUM>, and the gripping protuberances <NUM> can be configured to engage or dig into the outer pipe surface <NUM> of the pipe length <NUM>. In the present aspect, a row of gripping protuberances <NUM> disposed closest to the leading edge <NUM> can define a leading row <NUM> of gripping protuberances <NUM>.

The initial engagement position can describe a position of the gripper <NUM> when the leading row <NUM> first contacts the outer pipe surface <NUM> when rotating the gripper <NUM> in the engagement direction <NUM>. In the initial engagement position, the leading row <NUM> can rest in light contact with the outer pipe surface <NUM> under the bias of the spring clip <NUM>, and the leading row <NUM> of gripping protuberances <NUM> has not yet significantly dug into the outer pipe surface <NUM>. As shown, those gripping protuberances <NUM> not in the leading row <NUM> are disengaged from the outer pipe surface <NUM> in the initial engagement position.

In the initial engagement position, the gripper <NUM> does not substantially resist movement of the pipe length <NUM> in the insertion direction <NUM> into the socket <NUM>. The gripping protuberances <NUM> are biased to permit movement of the pipe length <NUM> in the insertion direction <NUM> without digging into the outer pipe surface <NUM>. The gripper <NUM> can rotate imperceptibly in the disengagement direction <NUM> to allow the leading row <NUM> of gripping protuberances <NUM> to slide across the outer pipe surface <NUM>.

However, moving the pipe length <NUM> in the withdrawal direction <NUM> outwards from the socket <NUM> can cause the leading row <NUM> of gripping protuberances <NUM> to "bite" and dig into the outer pipe surface <NUM>. Once the leading row <NUM> of gripping protuberances <NUM> dig into the outer pipe surface <NUM>, movement of the pipe length <NUM> in the withdrawal direction <NUM> causes rotation of the gripper <NUM> in the engagement direction <NUM>. The engagement end <NUM> of the gripper <NUM> can be configured to exert increasing pressure on the outer pipe surface <NUM> when the gripper <NUM> is rotated about the restraint pivot <NUM> in the engagement direction <NUM>. Rotational movement of the gripper <NUM> about the restraint pivot in the engagement direction <NUM> results in a radially inward component of movement of the engagement end <NUM> towards the gland axis <NUM> (shown in <FIG>). As the engagement end <NUM> rotates in the engagement direction <NUM> and moves radially inward, an increasing number of the gripping protuberances <NUM> engage the outer pipe surface <NUM>.

The radially inward component of movement of the engagement end <NUM> results in an inward pinching action of the pipe length <NUM> between opposing pairs of joint restraint assemblies <NUM>. The inward pinching action causes the gripping protuberances <NUM> to exert increasing pressure on the outer pipe surface <NUM>. The pipe length <NUM> resists the inward pinching action which prevents further rotation of the grippers <NUM> in the engagement direction which thereby resists further movement of the pipe length <NUM> in the withdrawal direction <NUM>. Movement of the pipe length <NUM> in the insertion direction <NUM> can relax the inward pinching action by rotating the grippers <NUM> slightly in the disengagement direction <NUM>.

Accordingly, each joint restraint assembly <NUM> reacts and self-adjusts to a withdrawal force acting on the pipe length <NUM> in the withdrawal direction <NUM> by exerting only as much force and pressure as required to prevent further movement of the pipe length <NUM> in the withdrawal direction <NUM>. The self-adjustment and variable engagement of the grippers <NUM> also allows each joint restraint assembly <NUM> to adjust to variations of the outer diameter of the pipe length <NUM>. Variation in the outer diameter of the pipe length <NUM> can be caused, for example and without limitation, by manufacturing tolerance, a wall thickness of the pipe length <NUM>, different dimensional specifications for pipe lengths <NUM> manufactured to different industry standards, ovality of the pipe length <NUM>, or deformation of the pipe length <NUM>. The joint restraint assemblies <NUM> are insensitive to such variations because each joint restraint assembly <NUM> can self-adjust independent of the other joint restraint assemblies <NUM>. In other aspects, the joint restraint assembly <NUM> can also be adjusted radially inward and outward to accommodate pipe lengths <NUM> of significantly different outer diameters. In other aspects, the grippers <NUM> can be provided with engagement ends <NUM> of different lengths, and the grippers <NUM> can be interchanged to accommodate pipe lengths <NUM> of significantly different outer diameters. For example, the grippers <NUM> of an aspect of the gland <NUM> configured for use with a <NUM>" pipe can be replaced with grippers <NUM> with an elongated engagement end <NUM> to convert the gland <NUM> for use with a <NUM>" pipe.

If the withdrawal of the pipe length <NUM> continues, the gripper <NUM> can continue to rotate in the engagement direction <NUM> until the lever end <NUM> of the gripper <NUM> contacts a stop surface <NUM> defined by the restraint base <NUM>, as shown in <FIG> is a detail view of the mechanical joint <NUM> of the pipe element assembly <NUM> taken from Detail <NUM> shown in <FIG> with the gripper <NUM> shown in the final engagement position. Contact between the gripper <NUM> and the stop surface <NUM> can prevent further rotation of the gripper <NUM> about the restraint pivot <NUM>. When the lever end <NUM> contacts the stop surface <NUM>, the gripper <NUM> can be in the final engagement position.

In the final engagement position, all of the gripping protuberances <NUM> can be engaged with the outer pipe surface <NUM>, thereby maximizing traction of the gripper <NUM> on the pipe length <NUM>. The stop surface <NUM> prevents the gripper <NUM> from further rotating in the engagement direction <NUM>, thereby preventing further movement of the pipe length <NUM> in the withdrawal direction <NUM> without bending the gripping protuberances <NUM> or shearing the gripping protuberances <NUM> or material from the outer pipe surface <NUM>. The pipe length <NUM> can still readily move in the insertion direction <NUM>, resulting in rotation of the gripper <NUM> in the disengagement direction <NUM> and ultimately reducing the inward pinching action acting on the pipe length <NUM>.

Engagement by the gripper <NUM> of each joint restraint assembly <NUM> can occur over a full range of motion between the initial engagement position and the final engagement position. The grippers <NUM> independently engage the pipe length <NUM>, and the degree of engagement can be based on numerous variables. The gripper <NUM> of each joint restraint assembly <NUM> can be in a different position and a different degree of engagement. For instance, a first gripper <NUM> of the mechanical joint <NUM> can be in the initial engagement position, a second gripper <NUM> of the mechanical joint <NUM> can be positioned between the initial engagement position and the final engagement position, and a third gripper <NUM> of the mechanical joint <NUM> can be in the final engagement position. Relevant variables include, but are not limited to, the outer diameter of the pipe length <NUM>, ovality of the pipe length <NUM>, angular deflection of the pipe length <NUM> relative to the gland axis <NUM> (shown in <FIG>), and a magnitude of force exerted on the pipe length <NUM> to insert or withdrawal the pipe length <NUM> from the socket <NUM>. As conditions change, each gripper <NUM> can independently react to increase or decrease engagement with the pipe length <NUM>. For example, if the pipe element assembly <NUM> is buried and settles over time or is subjected to a disruptive event such as an earthquake, each individual joint restraint assembly <NUM> can adjust independently to the new conditions of tension and angular alignment of the pipe length <NUM>.

<FIG> is a detail view of the mechanical joint <NUM> of the pipe element assembly <NUM> taken from Detail <NUM> shown in <FIG> with the gripper <NUM> shown in a lifted position. The lifted position is not a normal operating position, but can exemplify the ability of the joint restraint assembly <NUM> to compensate and adjust for misalignment during installation of the gland <NUM> over the pipe length <NUM>.

In the lifted position, the gripper <NUM> can lift off of the restraint pivot <NUM> such that the gripper bearing surface <NUM> at least partially breaks contact with the restraint bearing surface <NUM>. In the lifted position, the engagement end <NUM> can move radially outwards with respect to the gland axis <NUM> (shown in <FIG>) further than normally allowable in the disengaged position of <FIG>. The ability for the gripper <NUM> to lift off of the restraint pivot <NUM> can provide additional clearance for inserting the pipe length <NUM> through the gland <NUM>. In other aspects, the restraint pocket <NUM> can be sized and shaped to prevent lifting of the gripper <NUM> relative to the restraint pivot <NUM>. In other aspects, the restraint pivot <NUM> can be configured to prevent lifting of the gripper <NUM>. For example, in some aspects, the restraint pivot <NUM> can be a bolt, a rod, or a similar fastener extending through a bore defined by the gripper <NUM>.

<FIG> is a side view of the gripper <NUM> of <FIG>. The gripper <NUM> can define a first gripper surface <NUM> and a second gripper surface <NUM> disposed opposite from the first gripper surface <NUM>. The gripper bearing surface <NUM> can be defined by a portion of the first gripper surface <NUM>. The second gripper surface <NUM> can define the trailing edge <NUM>, and the first gripper surface <NUM> can define the leading edge <NUM>. The gripper <NUM> can also define a top gripper surface <NUM> disposed on the lever end <NUM> opposite from the plurality of gripping protuberances <NUM>. The gripper bearing surface <NUM> can be shaped complimentary to the restraint bearing surface <NUM> (shown in <FIG>). The gripper bearing surface <NUM> can define a gripper radius of curvature R<NUM> which can be substantially equal to the pivot radius of curvature R<NUM> (shown in <FIG>).

A contour of the edges of the plurality of gripping protuberances <NUM> can define an engagement radius of curvature R<NUM> of the gripping protuberances <NUM>. The engagement radius of curvature R<NUM> can smoothly roll the gripping protuberances <NUM> into increasing engagement with the outer pipe surface <NUM> (shown in <FIG>) as the pipe length <NUM> is moved in the withdrawal direction <NUM> (shown in <FIG>) and the gripper <NUM> is rotated in the engagement direction <NUM> (shown in <FIG>). The rolling of the gripping protuberances <NUM> can smoothly increase pressure applied to the pipe length <NUM> by each gripper <NUM>. A horizontal offset between a center point of the radius of curvature R<NUM> and a center point of the gripper radius of curvature R<NUM>, among other variables, can also affect a magnitude to the inward pinching action of the engagement end <NUM> of the gripper <NUM>. By increasing the horizontal offset, a radially inward component of the motion of the engagement end <NUM> can be increased when rotating the gripper <NUM> in the engagement direction <NUM>. By decreasing or eliminating the horizontal offset, the radially inward component of the motion of the engagement end <NUM> can be minimized when rotating the gripper <NUM> in the engagement direction <NUM>.

The contour of the edges of the gripping protuberances <NUM> can effectively act as a cam profile controlling the pressure and stress exerted on the pipe length <NUM> upon withdrawal. In the present aspect, the engagement radius of curvature R<NUM> can define a constant value. In other aspects, the contour of the edges of the gripping protuberances <NUM> can define a different shape without a constant engagement radius of curvature R<NUM>. In other aspects, the edges of the gripping protuberances <NUM> can all be coplanar. In such an aspect, the stress and pressure exerted by the engagement end <NUM> can reach a maximum between the initial engagement position and the final engagement position, and the stress and pressure can then reduce as the engagement end <NUM> rolls over center into the final engagement position. In such an aspect, the gripper <NUM> can be biased to remain in the final engagement position, and the pipe length <NUM> can be subjected to reduced residual stresses in the final engagement position.

In the present aspect, a center row <NUM> of gripping protuberances <NUM> can define a leading surface <NUM> and a trailing surface <NUM>. Each of the leading surface <NUM> and the trailing surface <NUM> can be substantially planar. In the final engagement position, the trailing surface can be substantially perpendicular to the gland axis <NUM> (shown in <FIG>). An engagement angle A<NUM> can be defined between the leading surface <NUM> and the trailing surface <NUM>, and the center row <NUM> can define an angled profile. The angled profile of the center row <NUM> can be configured to slide over the outer pipe surface <NUM> when the pipe length <NUM> is moved in the insertion direction <NUM> (as shown in <FIG>) and to bite into the outer pipe surface <NUM> when the pipe length <NUM> is moved in the withdrawal direction <NUM> (as shown in <FIG>). In the present aspect, the engagement angle A<NUM> can have a value substantially equal to <NUM> degrees; however, this value should not be viewed as limiting. In other aspects, the value of the engagement angle A<NUM> can range from <NUM> degrees to <NUM> degrees. In some aspects, some or all of the gripping protuberances <NUM> can each define the engagement angle A<NUM>.

In the present aspect, the leading row <NUM> of gripping protuberances <NUM> can define a leading surface <NUM> and a trailing surface <NUM>. The leading surface <NUM> can be substantially planar and the trailing surface <NUM> can be a curved surface swept slightly backwards towards the trailing edge <NUM>, thereby defining a curved profile. The curved surface of the trailing surface <NUM> can aid the leading row <NUM> in biting into the outer pipe surface <NUM> when the pipe length <NUM> is moved in the withdrawal direction <NUM> (as shown in <FIG>).

In various other aspects, the angled profile of the center row <NUM> and the curved profile of the leading row <NUM> can be exemplary of any of the gripping protuberances <NUM>. In some aspects, all or some of the gripping protuberances <NUM> can define the angled profile. In other aspects, all or some of the gripping protuberances <NUM> can define the curved profile. In the present aspect, the gripping protuberances <NUM> can define a mix of curved profiles and angled profiles.

<FIG> is a perspective view of the gripper <NUM> of <FIG>. As shown, the plurality of gripping protuberances <NUM> can comprise teeth <NUM> and ribs <NUM>. In the present aspect, the ribs <NUM> can be disposed proximate the trailing edge <NUM>, and the teeth <NUM> can be disposed proximate the leading edge <NUM> (shown in <FIG>). For example, the leading row <NUM> can be teeth <NUM> in the present aspect.

The ribs <NUM> can each define a rib knife edge <NUM> extending across a width of the respective rib <NUM>. In the present aspect, the gripper <NUM> can define a width of <NUM>", and the rib knife edges <NUM> can each define a length of <NUM>" long; however, the width of the gripper <NUM> and the length of the rib knife edge <NUM> should not be viewed as limiting. The grippers <NUM> can range from <NUM>" to <NUM>" in width in various aspect, but can have widths outside this range in other aspects. The width can be dependent upon, for example and without limitation, an outside diameter of the pipe length <NUM> as well as a number of grippers <NUM> engaging the pipe length <NUM> and an operating pressure of the pipe length <NUM>. In the present aspect, each rib knife edge <NUM> can be substantially linear; however in other aspects, each rib knife edge <NUM> can be curved or scalloped. For example, each rib knife edge <NUM> can be curved to compliment a radius of curvature of the outside diameter of the pipe length <NUM> in order to increase engagement area between each gripper <NUM> and the pipe length <NUM>. In some aspects, each rib knife edge <NUM> can be serrated.

Each tooth <NUM> can define a tooth knife edge <NUM> extending across a width of the respective tooth <NUM>. In other aspects, each tooth <NUM> can define a tooth point (not shown) instead of a tooth knife edge <NUM>. In the present aspect, each tooth knife edge <NUM> can be linear; however, in other aspects, each tooth knife edge <NUM> can be curved or serrated. The teeth <NUM> can be separated by notches <NUM> disposed between adjacent teeth <NUM>. The tooth knife edges <NUM>, the tooth points (not shown), and the rib knife edges <NUM> can each be configured to dig into the outer pipe surface <NUM> (shown in <FIG>). The teeth <NUM> can be separated by notches <NUM> disposed between adjacent teeth <NUM>. The teeth <NUM> and notches <NUM> can be configured to reduce available contact area of the collective tooth knife edges <NUM> compared to the rib knife edges <NUM> which can increase contact pressure at the tooth knife edges <NUM> of the teeth <NUM>. Increasing contact pressure at the tooth knife edges <NUM> of the teeth <NUM> can aid the teeth <NUM> in digging or cutting into the outer pipe surface <NUM>.

In the present aspect, the teeth <NUM> can be arranged in two teeth rows <NUM>; however, in other aspects, the teeth <NUM> may not be arranged in rows and instead can be positioned in other arrangements such as a staggered arrangement or any other suitable arrangement. Other aspects can comprise greater or fewer teeth rows <NUM>. In the present aspect, the ribs <NUM> and the teeth rows <NUM> can be substantially parallel to the trailing edge <NUM>; however in other aspects, the ribs <NUM> and the teeth rows <NUM> can be diagonally-oriented relative to the trailing edge <NUM>. In some aspects, all of the gripping protuberances <NUM> can be teeth <NUM>, and in other aspects, all of the gripping protuberances <NUM> can be ribs <NUM>. The ribs <NUM> and teeth <NUM> can be disposed in any arrangement.

The second gripper surface <NUM> can define a gripper pocket <NUM> extending into the gripper <NUM>. The gripper pocket <NUM> can be a blind hole which does not extend completely through the gripper <NUM>. In the present aspect, the gripper <NUM> can be biased towards engagement with the pipe length <NUM> by the spring clip <NUM> (shown in <FIG>); however, in other aspects, a coil spring (not shown) can be positioned within the gripper pocket <NUM>, and the coil spring can bias the gripper <NUM> towards engagement with the pipe length <NUM>. Alternatively, in some aspects, the gripper pocket <NUM> can receive the retention tab <NUM> (shown in <FIG>) to locate and retain the spring clip <NUM>.

A deactivation catch <NUM> can also be defined at the lever end <NUM> of the gripper <NUM>. In the present aspect, the deactivation catch <NUM> can be a notch extending through the lever end <NUM> from the second gripper surface <NUM> to the first gripper surface <NUM> (shown in <FIG>) and inward from the top gripper surface <NUM> (shown in <FIG>). In other aspects, the deactivation catch <NUM> can be a through hole which extends through the lever end <NUM> from the second gripper surface <NUM> to the first gripper surface <NUM> but can be enclosed by the top gripper surface <NUM> to form an aperture rather than a notch. In other aspects, the deactivation catch <NUM> can be a blind hole which does not extend completely through the gripper <NUM> to the first gripper surface <NUM>. The deactivation catch <NUM> can also define a countersunk shoulder <NUM> disposed around the notch, the through hole, or the blind hole. The deactivation catch <NUM> can be configured to engage some aspects of the deactivation mechanism <NUM>, as shown and further described below with respect to <FIG> and <FIG>.

<FIG> is a perspective view of the spring clip <NUM> of <FIG>. The retention tab <NUM> can be disposed on a retention leg <NUM>. The retention leg <NUM> can be disposed opposite from the engagement leg <NUM>. In some aspects, the retention tab <NUM> can define a slit (not shown) which can allow the retention tab <NUM> to spread apart in order to frictionally engage the locator bore <NUM> (shown in <FIG>). In other aspects, the retention tab <NUM> can comprise petals (not shown) defined by intersecting slits configured to frictionally engage the locator bore <NUM>. The spring clip <NUM> can demonstrate positional memory, and the engagement leg <NUM> can be configured to repeatedly elastically deform relative to the retention leg <NUM> without plastically deforming or taking a permanent set. The spring clip <NUM> can comprise a material such as spring steel or any other suitable material. In the present aspect, the spring clip <NUM> can be a flat spring or V-spring; however in other aspects, the spring clip <NUM> can be a wire spring or any other suitable type of spring.

<FIG> is a perspective view of the gland <NUM> of <FIG>. In the present aspect, the gland <NUM> can define six restraint bases <NUM>. The number of restraint bases <NUM> should not be viewed as limiting, however. Each gland <NUM> can define greater or fewer than six restraint bases <NUM>. The number of restraint bases <NUM> can also vary with a size of the gland <NUM>. For instance, an aspect configured for use with a <NUM>" diameter pipe can define more restraint bases <NUM> than an aspect configured for use with a <NUM>" diameter pipe. In the present aspect, the restraint bases <NUM> can also be evenly distributed around the annular ring <NUM> of the gland <NUM>, and the restraint bases <NUM> can be distributed as opposing pairs 1002a,b,c of restraint bases <NUM>. In other aspects, such as when the gland <NUM> defines an odd number of restraint bases <NUM>, the restraint bases <NUM> may not be distributed as opposing pairs.

In the present aspect, each restraint base <NUM> can define a pair of sidewalls <NUM> and the respective restraint pivot <NUM>. In the present aspect, the sidewalls <NUM> and the restraint pivot <NUM> can be integrally formed with the gland <NUM>. In other aspects, the restraint base <NUM> can be a separate component which can be fastened or attached to the gland <NUM>. In the aspect of <FIG>, the sidewalls <NUM> of the restraint base <NUM> can be integrally formed with the gland <NUM>, and the restraint pivot <NUM> can be a separate component fastened to the sidewalls <NUM>. In other aspects, each restraint base <NUM> can define multiple restraint pivots <NUM>, and multiple grippers <NUM> (shown in <FIG>) can be disposed within each restraint pocket <NUM>. In some other aspects, multiple grippers <NUM> can be engaged with a single restraint pivot <NUM>.

The sidewalls <NUM> of each restraint base <NUM> can define a pair of sidewall surfaces <NUM>. In the present aspect, the sidewall surfaces <NUM> of each restraint base <NUM> can be substantially parallel and can be in a facing relationship. The stop surface <NUM> can be substantially perpendicular to the sidewall surfaces <NUM>, and the stop surface <NUM> can extend between the sidewall surface <NUM>. The sidewall surfaces <NUM> and the stop surface <NUM> of each restraint base <NUM> can define the respective restraint pocket <NUM>.

The stop surface <NUM> of each restraint base <NUM> can define a spring groove <NUM> recessed into the respective stop surface <NUM>, and the locator bores <NUM> can be disposed within the respective spring grooves <NUM>. The spring grooves <NUM> and the locator bores <NUM> can cooperate to position and retain the spring clips <NUM> (shown in <FIG>) within each restraint pocket <NUM>, respectively. The gland <NUM> can also define a plurality of fastener holes <NUM>, each configured to receive a one of the fasteners <NUM>.

<FIG> is a perspective view of another aspect of the gland <NUM>. In the present aspect, the restraint pivots <NUM> can be a separate component which can each be attached to the respective restraint base <NUM> by a pair of fasteners <NUM>. In the present aspect, the fasteners <NUM> can be socket-head screws which can extend through a pair of countersunk bores <NUM> defined by each restraint pivot <NUM> and into the respective sidewalls <NUM>. Each sidewall <NUM> can define a pivot notch <NUM> sized and shaped complimentary to the restraint pivots <NUM>. Each restraint pivot <NUM> can be received and secured within a pair of pivot notches <NUM> of each respective restraint bases <NUM>. Removable restraint pivots <NUM> can be desirable in some aspects in order to provide for easier manufacturing methods. The removable restraint pivots <NUM> can also be made of a different material from the gland <NUM>. For example, the gland <NUM> can comprise cast iron, and the removable restrain pivots <NUM> can comprise a material such as bronze which demonstrates desirable bearing properties such as high hardness values and low friction coefficients. Removable restraint pivots <NUM> can also be used with aspects of the grippers <NUM> which define gripper bearing bores (not shown) rather than gripper bearing surfaces <NUM>. In such aspects, the removable restraint pivots <NUM> can be passed through the gripper bearing bores in order to mount the grippers <NUM>.

<FIG> is a cross-sectional view of the gland <NUM> of <FIG> taken along line <NUM>-<NUM> shown in <FIG>. <FIG> is a cross-sectional view of another aspect of the gland <NUM>. As shown in <FIG>, the restraint bases <NUM> can each comprise a pocket hood <NUM>, and the restraint bases <NUM> can each define a hooded restraint pocket <NUM>. Each pocket hood <NUM> can be disposed radially external to the respective hooded restraint pocket <NUM>, and each pocket hood <NUM> can cover a radially outer portion of the respective hooded restraint pocket <NUM>. The pocket hoods <NUM> can be configured to protect the hooded restraint pockets <NUM> against entry of debris, such as when the piping element assembly <NUM> (shown in <FIG>) is buried underground. Debris in the restraint pockets <NUM> or hooded restraint pockets <NUM> can jam the grippers <NUM> (shown in <FIG>) and spring clips <NUM> (shown in <FIG>) and prevent the grippers <NUM> from rotating about the respective restraint pivots <NUM>. As previously described, the pivot center axis P<NUM> of each restraint pivot <NUM> can be perpendicular to both the axial direction and the radial direction with respect to the gland axis <NUM>.

<FIG> is a perspective view of the mechanical joint <NUM> of <FIG> comprising another aspect of the deactivation mechanism <NUM>. The deactivation mechanism <NUM> of the present aspect can comprise an elastic member <NUM>, such as an O-ring, a rubber band, a bungee cord, or any other suitable stretchable material. The deactivation mechanism <NUM> can further comprise a plurality of deactivation blocks <NUM> which can each be attached to the elastic member <NUM> by a hooked portion <NUM> of each respective deactivation block <NUM>. Each deactivation block <NUM> can further define a blocking portion <NUM> and a neck portion <NUM>, and the neck portion <NUM> can be defined between the blocking portion <NUM> and the hooked portion <NUM>, thereby connecting the blocking portion <NUM> to the hooked portion <NUM>.

The neck portion <NUM> can be sized and shaped to engage the deactivation catch <NUM> defined by each gripper <NUM>. Under tension from the elastic member <NUM>, engagement between the deactivation catches <NUM> and neck portions <NUM> at each gripper <NUM> can bias the grippers <NUM> towards the deactivated position shown and described with respect to <FIG>. The blocking portion <NUM> can also fit between the lever end <NUM> of each gripper <NUM> and the respective spring clip <NUM>. The blocking portion <NUM> can provide a positive stop to prevent the grippers <NUM> from rotating towards the engagement position. The blocking portions <NUM> can also cover and protect the restraint pockets <NUM> (shown in <FIG>) to prevent debris from entering the restraint pockets <NUM>. In some aspects, the blocking portions <NUM> can define a wedge-shape configured to be inserted into the respective restraint pocket <NUM>.

To activate the mechanical joint <NUM>, each of the deactivation blocks <NUM> can be disengaged from the respective gripper <NUM>. The deactivation mechanism <NUM> can be left around the pipe length <NUM> as a method to store the deactivation mechanism <NUM> should the mechanical joint <NUM> need to be disassembled in the future. Alternatively, the elastic member <NUM> can be cut, and the deactivation mechanism <NUM> can be removed from the mechanical joint <NUM> and pipe length <NUM>. Attaching each deactivation block <NUM> to the elastic member <NUM> can ensure that no deactivation blocks <NUM> are accidentally left on the mechanical joint <NUM> after removal. In the present aspect, the deactivation blocks <NUM> can also be configured to automatically eject from the respective restraint pockets <NUM> (shown in <FIG>) when tension from the elastic member <NUM> is relieved.

<FIG> is a perspective view of the mechanical joint <NUM> of <FIG> comprising the gland <NUM> of <FIG> and another aspect of the deactivation mechanism <NUM>. In the present aspect, the deactivation mechanism <NUM> comprises a clamp <NUM>, such as a pipe clamp or hose clamp. The clamp <NUM> can comprise a band <NUM> and a tensioner <NUM>. The band <NUM> can be a metal band, a plastic band, a composite strap, or any other suitable strap or banding material. The tensioner <NUM> can be configured to tighten the band <NUM> or relax the band <NUM>, such as for installation and removal of the deactivation mechanism <NUM>, respectively. The tensioner <NUM> can be a jack bolt, a worm gear, a turnbuckle, or any other suitable tensioning mechanism. In other aspects, the clamp <NUM> may not comprise a tensioner <NUM>, and instead can comprise a buckle. In such aspects, the band <NUM> can be tensioned by a separate tensioning device and secured by the buckle.

The deactivation mechanism <NUM> can comprise deactivation blocks <NUM> which can be attached to the band <NUM> by a hooked portion <NUM> of each deactivation block <NUM>. The deactivation block <NUM> can further define a neck portion <NUM> and a blocking portion <NUM>. The neck portion <NUM> can be defined between the hooked portion <NUM> and the blocking portion <NUM>. The clamp <NUM> can secure the hooked portion <NUM> and the neck portion <NUM> in facing contact with the pocket hood <NUM> of each respective restraint base <NUM>. The blocking portion <NUM> can further cover the hooded restraint pocket <NUM> (shown in <FIG>) of each restraint base <NUM>. Each blocking portion <NUM> can prevent debris from entering the respective hooded restraint pocket <NUM> and also block the respective gripper <NUM> from rotating into engagement with the pipe length <NUM>.

Each deactivation block <NUM> can further define a blocking arm <NUM> and a blocking post <NUM> extending from the respective blocking portion <NUM>. The blocking arm <NUM> can be wider than the blocking post <NUM>, and the blocking arm <NUM> can be configured to engage the countersunk shoulder <NUM> (shown in <FIG>) and the blocking post <NUM> can be configured to extend into the deactivation catch <NUM> (shown in <FIG>) of the respective gripper <NUM>. The blocking portion <NUM>, the blocking arm <NUM>, and the blocking post <NUM> can cooperate to prevent engagement between the respective gripper <NUM> and the pipe length <NUM> by blocking the rotating motion of the respective gripper <NUM>.

In other aspects, individual deactivation blocks (not shown) can comprise the blocking portion <NUM>, the blocking arm <NUM>, and the blocking post <NUM> without being attached to the neck portion <NUM>. The individual deactivation blocks can individually engage a one of the grippers <NUM> without the use of an elastic member or clamp and can be retained by the force of the spring clip <NUM> (shown in <FIG>). In other aspects such as with the gland <NUM> of <FIG>, the individual deactivation blocks can engage the restraint pocket <NUM> to remain in position.

In practice, to couple the pipe length <NUM> to the piping element <NUM>, the gland <NUM> in the deactivated configuration can first be slid over the plain end <NUM> of the pipe length <NUM> with the engagement bevel <NUM> facing the plain end <NUM>. The gasket <NUM> can then be slid over the plain end <NUM> of the pipe length <NUM>, and the plain end <NUM> can be inserted into the socket <NUM> until the plain end <NUM> contacts the pipe shoulder <NUM>. The gasket <NUM> can be positioned in the gasket groove <NUM>. The fasteners <NUM> can be inserted through the notches <NUM> or bores <NUM> of the element flange <NUM> and through the corresponding fastener holes <NUM> of the gland <NUM>.

The fasteners <NUM> can be tightened, thereby drawing the gland <NUM> towards the element flange <NUM> and compressing the gasket <NUM> within the gasket groove <NUM>. Compressing the gasket <NUM> can press an inner gasket surface <NUM> of the gasket <NUM> against the outer pipe surface <NUM> of the pipe length <NUM>, thereby forming a seal between the gasket <NUM> and the pipe length <NUM>. Once the gland <NUM> has been fastened to the element flange <NUM>, and the seal between the gasket <NUM> and the pipe length <NUM> has been formed, the deactivation mechanism <NUM> can be removed from the gland <NUM>, thereby activating the joint restraint assemblies <NUM>. Upon activation of the joint restraint assemblies <NUM>, the gripper <NUM> of each joint restraint assembly <NUM> can rotate about the respective restraint pivot <NUM> to engage the pipe length <NUM>. Once engaged with the pipe length <NUM>, the joint restraint assemblies <NUM> can allow limited movement of the pipe length <NUM> in the withdrawal direction <NUM>; however, the joint restraint assemblies <NUM> prevent removal of the pipe length <NUM> from the socket <NUM>. In this context, the term "removal" indicates complete withdrawal of the pipe length <NUM> from the socket <NUM>.

Upon activation of the joint restraint assemblies <NUM>, each gripper <NUM> self-adjusts and engages the pipe length <NUM> based on variables such as the outside diameter of the pipe length <NUM>, the ovality of the pipe length <NUM>, and the angular deflection of the pipe length <NUM> from the gland axis <NUM>. For example, if the pipe length <NUM> demonstrates a high degree of ovality, upon activation some of the grippers <NUM> can rotate to the initial engagement position while other grippers can rotate to a position between the initial engagement position and the final engagement position. In situations in which the outer diameter of the pipe length <NUM> is significantly undersized, the grippers <NUM> can rotate to the final engagement position upon initial activation. As the pipe length <NUM> moves in either the insertion direction <NUM> or the withdrawal direction <NUM> or angularly deflects relative to the gland axis <NUM>, the joint restraint assemblies <NUM> individually adjust to increase engagement and stress on the pipe length <NUM> as needed or to decrease engagement and relieve stress on the pipe length <NUM> if not required to restraint the pipe length <NUM>. The self-adjusting nature of the joint restraint assemblies <NUM> can be desirable over other joint restraint methods which induce high levels of residual stress in pipe lengths <NUM> which can lead to cracking, creep and deformation, or failure over time of the connection.

In some applications, the engagement ends <NUM> of the grippers <NUM> can be treated with a substance or a chemical which can bond the gripping protuberances <NUM> to the outer pipe surface <NUM>. For example, an adhesive such as a cement, an epoxy, a glue, a mastic, or any other suitable adhesive can be applied to the grippers <NUM> to bond the gripping protuberances <NUM> to the pipe lengths <NUM>. Another example, a chemical agent configured to react and soften the material of the pipe lengths <NUM> can be applied to the gripping protuberances <NUM>, and the grippers <NUM> can chemically weld to the outer pipe surface <NUM> upon re-hardening of the material of the pipe length <NUM>.

The joint restraint assemblies <NUM> can also be desirable over connection methods which require special end configurations for the pipe lengths <NUM> rather than plain ends <NUM>. For example, some connection methods require that the pipe length <NUM> define a feature such as a flange, groove, or threading at the end of the pipe length <NUM>. Unfortunately, in field environments, a required length of the pipe length <NUM> for a given application can vary, and therefore the pipe lengths <NUM> cannot be provided off-the-shelf in the required length for each application. Consequently, the ends of the pipe lengths <NUM> must be prepared in the field for such methods, such as by welding on a flange, machining a groove, or cutting threads. Such methods can be time consuming and require expensive equipment and skilled labor to perform in the field. By contrast, with the mechanical joint <NUM> and the joint restraint assemblies <NUM> shown, the pipe length <NUM> can simply be cut to the required length, and the mechanical joint <NUM> can be quickly completed with only a wrench or other simple hand tools.

The joint restraint assemblies <NUM> are not limited to use in mechanical joints <NUM>, and the joint restraint assemblies <NUM> can be disposed directly on the piping element <NUM> rather than on the gland <NUM>. For example, the piping element <NUM> can be a coupling which forms a seal with the pipe lengths <NUM> by a means other than compressing the gasket <NUM> with the gland <NUM>. In such application, the joint restraint assemblies <NUM> can be attached directly to the pipe coupling. In other aspects, the joint restraint assembly <NUM> can be attached to piping elements <NUM> such as valves, hydrants, couplings, fittings, or other suitable types of piping elements.

Claim 1:
A mechanical joint comprising:
a piping element (<NUM>), the piping element comprising an element flange (<NUM>, 122a, 122b), the piping element defining a socket (<NUM>, 222a, 222b) extending inwards from the element flange;
a pipe length (<NUM>, 102a, 102b), the pipe length extending through the element flange into the socket, the pipe length defining an outer pipe surface(<NUM>, 204a, 204b); and
a gland (124a, 124a, 124b), the pipe length extending through the gland, the gland comprising a joint restraint assembly (<NUM>), the joint restraint assembly comprising:
a restraint base (<NUM>) defining a restraint pocket; and
a gripper (<NUM>, 232a, 232b) disposed within the restraint pocket, the gripper configured to rotate in the restraint pocket, the gripper further configured to engage the outer pipe surface to prevent removal of the pipe length from the socket,
wherein
the gripper defines an engagement end (<NUM>) and a lever end (<NUM>) disposed opposite from the engagement end;
the gripper comprises a plurality of gripping protuberances (<NUM>) disposed on the engagement end;
at least a one of the gripping protuberances engages the outer pipe surface; characterised in that
the gripper is configured to be prevented from rotating towards engagement with the outer pipe surface by a deactivation mechanism, when in a deactivated configuration.