WO2006088451A1

WO2006088451A1 - Pipe coupling

Info

Publication number: WO2006088451A1
Application number: PCT/US2005/004833
Authority: WO
Inventors: Ajit Singh Gill
Original assignee: Ajit Singh Gill
Priority date: 2005-02-16
Filing date: 2005-02-16
Publication date: 2006-08-24

Abstract

A coupling to connect pipe, including lengths of pipe, valves, hoses, and pipe and hose fittings, includes a body to closely receive the end portion of the pipe to be coupled and jaw members to secure the pipe to be coupled in the coupling. The jaw members of the coupling may include a set of first class lever jaw members having a power arm and a weight arm mounted to the coupling body to establish a fulcrum for rotation of each lever jaw member about the fulcrum between an engaged position and a disengaged position with respect to the pipe end portion when received in the coupling body. Additionally or alternately, jaw members may be provided adapted to slide along the inner groove in the coupling body to move between a position spaced radially from the received pipe to allow the pipe to move into or out of the coupling body and a position securing the pipe in the coupling body.

Description

PIPE COUPLING

BACKGROUND OF THE INVENTION Field:

The invention is in the field of couplings to connect grooved or plain end portions of pipes, and to connect hoses valves, pipe fittings, expansion joints, and dead ends of pressure vessels.

State of the Art:

There are various types of mechanical couplings which employ various radial mechanical means, such as clamps and rings to secure the couplings to circumferential grooves on the ends of two pipes being connected. There are also my couplings, patented under U.S. Patent Numbers 5,387,017 and 5,868,441, each of which employ a set of camming jaw members mounted on the coupling body around the receiving opening, where, to engage or to disengage, the coupling jaw members move toward or away from a pipe received in the body. There are other U.S. Patents 5,794,988 and 6,186,560 by the inventor where expandable rings are employed to engage or to disengage the coupling. The new invented coupling is more economical to produce, and is easier than other couplings to connect plain end pipe. From here on the word pipe will encompass not only lengths of pipe, but also valves, hoses, and pipe and hose fittings where a connection is made to a pipe or other hoses or fittings.

SUMMARY OF INVENTION

According to the invention, a coupling to connect two opposite circumferential end portions of pipe includes a coupling body with a receiving opening therein so that the

Λ coupling body closely receives and surrounds the end portion of a pipe to be coupled. The coupling body includes a radial groove therein concentric with the axis of the coupling and a pipe inserted into the coupling, and which groove is positioned over the pipe when the end portion of the pipe is received in the coupling body. One or more jaw member is positioned in the groove and can be moved to a position in the groove with respect to the received pipe to secure the pipe in the coupling body. The jaw member may be a set of rigid lever jaw members mounted in the coupling so that a portion of the set of lever jaw members is located inside the radial groove. A portion of the set of lever jaw members preferably extends to the outside of the coupling body so that the jaw member can be operated from outside the coupling body. The set of lever jaw members each define a first class lever with a power arm and a weight arm. A first class lever has the fulcrum between the effort (the power arm of the lever) and the load (the weight arm of the lever). Thus, a separate power arm of the lever extends from the fulcrum of the lever and a separate weight arm extends from the fulcrum of the lever. By separate arms is meant that the power arm and weight arms are separate arms, although they may be formed by a single length of material with the fulcrum dividing the length of material into the power arm and the weight arm where the two arms have a common portion surrounding the fulcrum. In a preferred embodiment of the invention, the power arm of each lever is offset from the weight arm of the lever by an axle which forms the fulcrum of the lever. The words fulcrum and an axle will be considered as synonyms when describing the preferred embodiment. A portion of the weight arm furthest away from the fulcrum is arcuate, preferably concentric with a groove in the body of the coupling which accommodates it, which also makes it concentric with the end portion of a pipe to be coupled received in the coupling body receiving opening. The fulcrum axle at the junction of the power and weight arms is located in a gap or opening provided in the end of the coupling where the radial groove is interrupted with an opening from the radial groove to outside the coupling body. In the preferred embodiment, the power arm is situated outside the coupling body and runs approximately parallel to the weight arm situated inside the coupling body.

The power arm of the lever jaw can be operated on by a hand or hand held tool. Rotating the power arm in one direction moves the weight arm toward a pipe end portion received in the coupling body receiving opening, and rotating the power arm in the opposite direction moves the weight arm away from the pipe. The power arm is kept rotatably attached to the outer face body of the coupling body. Thus, the weight arm is engaged or disengaged with a pipe received in the coupling body receiving opening (the pipe having a plain surface or a groove in its end portion) by rotating the lever jaw about its fulcrum, using the power arm of the lever jaw. Each weight arm is locked in engaged position with the pipe by means of radial bolts passing through the end portion of the body of the coupling. The radial groove inside the end portion of the body of the coupling is provided with sufficient depth to accommodate the movement of the lever arm.

It may be necessary or unnecessary to employ locking bolts with the coupling when used with grooved or plain end pipe. With the grooved pipe, the end of the power arm outside the coupling body, situated against the outer face of the coupling, may be locked by a frictional fit. Friction may be provided in various ways for a friction fit.

The end portion of the coupling body which includes the groove in which the jaw member is located need not extend completely around the circumference of the pipe, but may extend only partially around the received pipe so the groove extends only partially around the received pipe. In such case the groove opens to outside the coupling body. The lever jaw member may be mounted in this groove, or a flat camming jaw member may be mounted in the groove such that movement of the camming jaw member results in radial movement of the camming jaw member in the groove between a position spaced radially from the pipe to allow the pipe to move into or out of the coupling body and a position in the groove securing the pipe in the coupling body. Alternately, with the groove opening to outside the coupling body, a flat jaw member without camming grooves may be inserted into the groove to secure the pipe in the coupling body or removed from the groove to allow the pipe to be inserted or removed from the coupling body. For different applications of the coupling, different types of gaskets are provided between the coupling and pipe end portions. In some application conventional "O" rings or other gaskets may be used with the coupling. At least one gasket is provided for the coupling to seal the exit of fluid from the pipes being joined. A predetermined length of gap between the ends of two pipes being joined may be provided for thermal expansion and to maintain the integrity of the gasket seal.

Also, according to the invention, a coupling for connecting to the end portion of a pipe includes a coupling body with a receiving opening therein so that the coupling body closely receives and surrounds the end portion of a pipe to be coupled. The coupling has an inner end taper and a set of jaw members slidably positioned in the inner end taper of the coupling body so that linear movement of the jaw members toward the end of the inner end taper causes movement of the jaw members radially inwardly of the coupling body against the end portion of the pipe when received in the coupling body. Linear movement of the jaw members in the opposite direction causes radial movement of the jaw members away from the received pipe to release the pipe from the coupling. Means, such as laterally extending slots through the inner end taper of the coupling body with bolts extending from the jaw members slidably through the slots, secure the jaw members to the coupling body. The inner end taper with accompanying jaw members can be provided in one end of the coupling or may be provided in both ends of the coupling. THE DRAWINGS

The best mode presently contemplated for carrying out the invention is illustrated in the accompanying drawings, in which: FIG. 1 is a transverse vertical section of the coupling of the invention taken through the lever jaws in engaged and locked position with the groove of a pipe to be coupled;

FIG. 2, a section similar to that of FIG. 1, taken on line 3-3 of FIG. 3, where relative positions of weight and power arms with respect to one another are shown;

FIG. 3, a longitudinal vertical section taken on line 2-2 of FIG. 2. where pipes are not shown, but only the coupling is depicted;

FIG. 4, a longitudinal vertical section of a bell type coupling of FIG. 1, where lever jaws are not show, only a diaphragm seal is depicted;

FIG. 5, a longitudinal vertical section of a two ended coupling of FIG. 1 taken on the line 1-1 of FIG. 1 showing two triangular type seals; FIG. 6, a longitudinal vertical section of a two ended coupling with inverted deformed

"U" type seal, mounted on two rings with slanted faces where the rings are welded to pipe end portions;

FIG. 7, a longitudinal vertical section of a coupling taken on the line 1-1 of FIG. 1, where a long and heavier diaphragm seal is used for hydraulic grip, where one end of couplings is fitted with removable griping jaws to facilitate the mounting of a heavier diaphragm seal;

FIG. 8, a transverse section similar to that of FIG. 1, showing a portion of the ^• coupling body removed and jaw members are reversed in the position;

FIG. 9, a view similar to that of FIG. 3, but showing a portion of the coupling body filled with sand or ceramic material to cut the weight of the coupling;

FIG. 10, a transverse section similar to that of FIG. 8, but showing camming jaws mounted in the coupling instead lever jaws;

FIG.l 1, a fragmentary section taken on the line 5-5 of FIG. 10; and

FIG. 12, a transverse section similar to that of FIG. 8, but showing a lever jaw in combination with a flat plate arcuate jaw.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENT All the drawings can be studied together. Whether the coupling is one ended (having inner groove Gl and lever jaw members J only in one end portion of the coupling body with invented means to couple pipe) or two ended (where the coupling has inner grooves Gl and G2 and lever jaw members J in both end portions of the coupling body with invented means to couple pipe) the mechanical means, such as the lever jaw members which are employed to engage the coupling with the pipe, remains the same. For different requirements, and for cost effectiveness, different types of gaskets are shown in the drawings. Therefore, more than one type of gasket may be depicted on any given pipe section illustration. It is pointed out that drawings are not to any particular scale. It is further pointed out that because of the simplicity of the drawings, if any element (such as a lever jaw or the bolt used to lock the lever jaw in place) is used more than once in the design, that element will be depicted by the same numbers and alphabets in the same drawing and in all other drawings as well.

First, the coupling for grooved end pipe, FIGS. 1 to 6, will be explained simultaneously. FIGS. 1 and 2 are the same, except that FIG. 2 shows a reverse view, and it shows the relative positions of weight and power arms with respect to each other. As shown in FIG. 1, the coupling has body C with outer diameter Cl and inner diameter C2. The depth of the inner groove Gl, which is used to accommodate lever jaws J, is depicted by the height between inner diameters C2 of the coupling body and groove diameter 31. The coupling C is shown to engage pipe 14 with inner and outer diameters 20 and 21 respectively. The two ends of lever J are shown by Jl and J2. Concentric with the coupling, an arcuate portion J4, of lever jaw J, is delineated by J2, 16 and J7. J4 is concentric with the coupling body, with the pipe, with the inner groove in the body of the coupling, and with the groove in the outer surface of the pipe. The section between J7 and J9 diverges from said arcuate section J4, by making an interior angle at J7 with J4, outward and away from the center of the coupling to the fulcrum and integral axle J3 of the lever jaw. The power arm J8 shown in FIGS. 2, 3,5 and 6 between J3 and J12, exits out of the coupling by making an offset interior angle with the weight arm at J9. The weight arm J5 and the power arm J8 are kept apart by means of circular stem J15 shown in FIG. 3. The power arm J5 preferably is replica of the weight arm J8. The section between of the power arm between Jl 1 and Jl 8 (shown in FIG. 3) diverges from the arcuate section J8 by making an interior angle at Jl 1 with J8. Lever jaw J is held in position to coupling body C by means of a fulcrum integral axle J3, located in a cut delineated by cut sides 32, 33, and 34, where groove Gl is also interrupted. The power arm J8, between J3 and J12, rotates the weight arm from J3 to J2, about the fulcrum J3. The portion of lever jaw J4, between J2 and J6, is designed to engage the groove of the pipe. The groove on the end portion of the pipe is indicated by 22.

Optional radial bolts may be provided to secure the unlocking of the power arms j8, but the power arms may be locked in place by friction fit against the outer faces Fl and F2 of the coupling body. Alternatively, secure locking of the lever arms may be accomplished by securing a locking tab J20 to the power arm of the lever with a hole therethrough which, when the arms are in position to secure the pipe in the coupling aligns with a hole through the end of the coupling body extending into the groove in the coupling. A bolt nl is inserted through the hole in the locking tab J20 and through the aligned hole in the coupling body to extend over lever jaw J and hold the weight arm and power arm in locked position as shown in FIG. 2. In low pressure pipes or hoses where frequent engaging and disengaging of the coupling is required, only one lever jaw J will be provided in the coupling. It is further pointed out that if high pressure in the pipe line requires the use of more than one or two lever jaws, then more than one or two lever jaws J will be provided for the coupling. The two pipes being connected in the Figures are shown by 14 and 14 A; their outer diameters are depicted by 21 and 21 A.

The mechanical means of lever jaw J has already been explained under FIGS. 1, 2, and 3. Therefore, they will not be discussed again unless the need arises, and only new elements in each Figure will be explained. In all of the drawings, the body of each coupling is shown by C, its outer diameter is shown by Cl , and its inner diameter by C2. The length of each coupling between its outer opposite ends, is indicated by Fl and F2. Outer faces Fl and F2 also provide the outer walls 27 and 27A for grooves Gl and G2 respectively.

FIGS. 3 and 5 and 6 show two a ended couplings, and FIG. 4 shows a one ended coupling. In FIG. 4 the one ended coupling is integrated either with a traditional pipe or with a hose shank. Whichever the case, the pipe or hose shank is shown by 14A.

To make coupling easily understood, the coupling in FIG. 3 is shown without any pipe. It depicts a longitudinal vertical section taken on line 2-2 of FIG. 2. All the elements of FIG. 3 have been discussed with FIGS. 1 and 2.

FIG. 4 employs a diaphragm type of gasket seal, which will also be explained under FIG. 7. Diaphragm seal 1 in FIG. 4 is a miniature seal of the same design as in FIG. 7. Seal 1 is provided with openings 12 and 12A to pressurize the seal with fluid in the pipe line. The outer surface 21 of pipe 14 provides a seat for gasket 1. Through cavity 19 and openings 12 and 12 A, fluid reaches internal cavities 13 and 13 A, and pressurizes diaphragm seal 1, thus blocking the exit of fluid between 14 and 11. The lever jaws with their weight and power arms are not shown in FIG. 4. FIG. 3 shows clearly groove Gl for the lever jaw weight arm, and the groove 22 constructed in the ring welded to the pipe or around the pipe.

FIG. 5 shows the invented coupling holding two pipes 14 and 14A together. It also shows two seal gaskets mounted over rings, which rings may be welded to the ends of the pipes or mounted around the end portions of pipes. The power arms J8 are held in place against the end faces Fl and F2 by means of a frictional fit or by means of frictional depressions provided in said faces Fl and F2. The triangular seals 47 and 47A depicted by their sides 50, 51, 52 and 5OA, 5 IA, 52 A₄ respective^ are mounted in corresponding triangular grooves. The seal may be a solid seal or it may be provided with a hollow interior which can be energized by the fluid in the pipe line. The fluid in cavities 53 and 53A exert pressure outwardly toward the coupling body and the fluid provided by the gap G pushes the seals outward parallel to the axis of the pipe. Thus the resultant force is such that it seals the fluid. The power jaws J8 ( shown in FIG. 2) can be pried out by pushing a tool between the arm J8 and pipe.

The coupling shown in FIG. 6 is the same coupling as shown in FIG. 3. The dotted pipes 14 and 14A are merely indicative of pipes which the coupling would hold together. In FIG. 6 during the push of the two pipes 14 and 14A₁₁ the original "U" type of gasket 47 is deformed. The seal 47 is partially located in the inner coupling body and partially between the opposite ends of pipes between slanting ends 16 and 16 A. In FIG. 6, gasket seal 47 is located in the corresponding cavity 52 created by the pipes 14 and 14A and the coupling C. The two arms of 47 are shown by 48 and 49. Fluid enters cavity 52, through gap G between pipes, and pressurizes the gasket. The original flare of the gasket, between arms 48 and 49, is reduced by slants 51 and 5 IA, when the pipes are pushed into the receiving openings of the coupling, during mounting.

In FIG. 7, the diaphragm gasket seal 1, as shown in FIG. 4, is slightly modified by providing inclines 3 and 3 A in the outer surface of the diaphragm, rather than in the back of the diaphragm. The coupling in FIG. 7 is provided with at least one lever jaw J (shown in FIGS, previously discussed) on one side of the coupling; the other side of the coupling is provided with preferably a set of four jaws (where two jaws of the set are indicated by 60 and

62) held slidably inside the coupling body by means of slants depicted by 6OA and 62 A of jaws 60 and 62. The incline 3 A is extended clearly to the outer face F2 of the coupling body to make it easier to mount the heavier diaphragm seal 1 inside the coupling body, particularly it is needed in the case of small size couplings. Opposite at the center of each of the jaws depicted by 60 and 62, a linear radial opening or slot for the travel of bolts 73 is provided. Each jaw is provided an extension 69 fitted under 15 A. The expanding push of the jaws shown by 60 and 62 enlarge the diameter of 15 A, and by tightening the bolts 73, the jaws are locked in place with the expanded diameter of said jaws, which further eases the mounting of the pipe 14 A. The coupling C provides a cavity 19 in conjunction with pipes 14 and 14A for diaphragm gasket seal 1. The cavity is delineated by inner surfaces 28, 25, 26, 25A and 26A in the coupling body, and end portions of pipes 14 and 14a. Except for the pipes 14 and 14 A, gasket 1 is delineated by numbers from 1 to 15. The two ends 2 and 2 A of gasket 1 are abutted against two sides 26 and 26A of cavity 19. The end portions of the gasket with the inclines 3 and 3 A are depicted by 15 and 15 A. Fluid enters the diaphragm gasket seal through the gap G, between the ends 16 and 16A of pipes 14 and 14A, and then reaches inner cavities 13 and 13 A through openings 12 and 12 A. The fluid simultaneously pressurizes the entire diaphragm seal, including portions 11 between 17 and 18, and portion 1 IA between 17A and 18 A, with 11 and 11 A being positioned around 14 and 14A respectively. Thus the exit of the fluid, between pipe 14 and gasket portion 11, and pipe 14A and gasket portion 1 IA, is blocked. Openings 12 and 12A are located in the section between 6 and 6 A, away from the ends 16 and 16A of 14 and 14 A. Under fluid pressure, ends 15 and 15A are squeezed by the components of pressure force, and create hydraulic grips, which become complementary force to help lever jaws J to hold the pipes in place. Thus, plain ended pipe can be connected by the coupling of this invention. The interior section between faces 10 and 1OA of gasket 1 makes a bell type curve indicated by curves 5, 7 and 5 A, where the bell accommodates the designed deflection of the pipe. The length of each of the sections 11 and 1 IA of the diaphragm, in contact with the pipes, is preferably kept equal to half of the outside radius of the pipe, which is equated against the pressure acting against the shut off valve. At the time of mounting of diaphragm gasket seal 1 around the pipe, the angular section of gasket shown rising from the pipe's surface is some what stretched in its diameter and the rest portion of the diaphragm running toward the end of the coupling body merely hugs the surface of the pipe. Till the diaphragm is pressurized by the fluid, opposite angular portions of the bell section of the gasket nearest to the pipes and ends 15 and 15A of diaphragm 1 block the exit of the fluid from the pipe line.

Lever jaws J in FIG. 7 where plain or smooth pipe ends are coupled are preferably provided with gripping surfaces on the arcuate portions which contact the surface of the pipe end portion to be coupled. Such gripping surfaces may be provided by rubber material shown by ring P or by plastic or abrasive material to provide frictional contact with the pipe. By receding the bolts B away from J4, and by lifting the weight arms J4, pipe 14 is pushed into the receiving opening of the coupling, then the second pipe 14A is pushed into the second receiving openings of the coupling, and bolts 73 are tightened before the pipe line is pressurized by the fluid. The optional bolt 24 keeps the coupling fixed between the end 16 and 16A of pipes 14 and 14A. The rest of the coupling is explained previously.

FIG. 8 is the same as FIGS. 1 and 2. To reduce the weight of the coupling, a portion of the coupling body is removed, and the jaws are placed in reverse position next to each other. An alternative design to operate lever arm J and power arm J8 together is shown in FIGS. 8 and 9. The square stem Jl 5 is provided with a corresponding opening for a bolt B. The square stem may be constructed as an integral part of lever arm J. Approximately half of the housing 46 shown in FIGS. 1 and 2 is removed in FIG. 8. The thickness of the roof of housing 46 is indicated by 36 and outer and inner surfaces are shown by 37 and 31 on the right side of FIG. 8. The arcuate length of the housing is depicted between 32A and 34A. Thus, wall Fl and roof 36 for the lever jaws does not appear on left side of FIG. 8. An alternative method to reduce weight of the coupling is also depicted in FIG. 9.

FIG. 9 shows a rectangular section S filled with a sand casting ring which is left intact in the casting of the coupling body C. An alternative design to connect lever jaw J to power arm j8 is shown on the top left side of the coupling. Bolt B shown with its head Bl and threaded stem B2 is mounted through square stem Jl 5. Square stem Jl 5 may be secured to J by welding or may be formed integrally with J. Threaded portion B2 is screwed into the corresponding threaded hole in coupling body C. Thus by removing the bolts B, the jaws J can be removed from the jaw housing. FIGS. 10 and 11 can be studied together. FIGS. 10 show that while one end of the coupling is provided at least one lever jaw with power arm the other end of the coupling can be provided with at least one camming jaw or two jaws. FIG. 10 shows one end of the coupling provided with two camming jaws depicted by j. The camming jaws j are mounted in housing groove Gl which has outer wall Fl and roof depicted by 36 having inner and outer surfaces 31 and 37, respectively. FIG. 10 depicts a transverse vertical section taken through said housing passing through camming grooves gl and g2 in the body of the two jaws depicted by j. The arcuate length of each jaw is shown between j 1 and j2. Each jaws j is movably held inside of Gl by means of frictional pins bl and b2 driven through wall Fl. Pins bl and b2 can be bolts as well as driven through Fl into camming grooves gl and g2. Radial flange H is welded to the end of jl of j or that flange is constructed integrally with j. Welding is shown by W. Opening Hl is provided in flange H. A locking bolt b3 is passed through opening Hl and its threaded end b4 lockingly can be driven into the coupling body C. Unlike the "U" jaws in the inventor's coupling in his Patent Number 5,387,017; each arcuate flat jaw is moved separately in the opposite direction. Movement of the jaw in one direction by means of flange H moves the jaw out of the pipe groove 22 to free the coupling from pipe 14, and moving the jaw in the opposite direction lowers the jaw into the groove 22 to lock the coupling to pipe 14. By loosening bolt b3, each jaw j can be rotated around groove 22 by means of bolt handle b3.

The invented coupling has the distinct economical advantage of providing two couplings with the same coupling body, where two types of jaws can be used to meet the requirement and preference of the costumer.

FIG. 12 shows one end of the coupling provided with one lever jaw in combination with an arcuate flat plate j aw. The flat plate j aw is shown by V having inner and outer diameters V2 and Vl respectively. An arcuate length of the jaw V is depicted by V3 and V4. The end flange V4 is provided with an opening V5 for a bolt which can lockingly can be driven into coupling body C. The flat plate arcuate jaw V can be mounted once the lever jaw J has been locked in the groove of the pipe 14. Similarly V can be released from the groove of pipe 14 before or after the lever jaw J is unlocked from the groove of pipe 14.

This invented coupling has another distinct economical advantage in that it provides a coupling with combinations of flat plate camming jaws or plan flat plate jaws, where lever jaw can be locked into the groove of the pipe very quickly and the other types of jaws are locked in after locking the lever jaw with the groove of the pipe. Thus coupling has wider range to meet the requirement and preference of the costumer.

The coupling of the invention is particularly suited for use with a flange, such as shown in pending US Application Serial No. 10/446,302, which is secured, such as by welding, to the end of a pipe to provide a groove in the end of the pipe and to provide an advantageous sealing surface for confronting joined pipes. It is understood that one end of the invented coupling may have a different type of connection, such as a flange connection, a threaded connection, a ring connection, or any other type of jaw connection, to meet different requirements and conditions in making connections with pipes, hoses, pipe and hose fittings, and valves. For dead ends, the coupling is used as a one ended coupling which is provided with a blocking dead end plate. It is further understood that various changes may be made in adapting the invention to different embodiments without departing from the broader inventive concepts disclosed herein and comprehended by the claims that follow.

It is further understood that in some applications the length of the lever jaws can be much smaller than shown in the FIGS. It is also understood that a partial gap between any two jaws can be filled with a flat or suitable "U" jaw.

Claims

I claim:

1. A coupling for attachment to the end portion of a pipe, comprising: a coupling body to closely receive the end portion of the pipe to be coupled therewith; a set of first class lever jaw members having a power arm and a separate weight arm extending from an axle which forms a fulcrum, said axle having a fulcrum mounting portion extending away from the arms; and a mounting hole in the coupling body receiving the fulcrum mounting portion of the set of lever jaw members therein as the sole mounting of the set of lever jaw members to the coupling body to establish the fulcrum for rotation of each lever jaw member about the fulcrum where rotation of the power arm about the fulcrum causes rotation of the weight arm about the fulcrum to an engaged position or to a disengaged position with respect to the end portion of the pipe when the pipe is received in the coupling body.

2. A coupling for attachment to the end portion of a pipe according to Claim 1, wherein the coupling is secured to the end of a pipe to couple to the end of another pipe.

3. A coupling for attachment to the end portion of a pipe according to Claim 1, wherein the coupling joins two pipes in end to end relationship, each pipe having an end portion, wherein the coupling body is adapted to closely receive the end portion of each of the two pipes to be joined in end to end relationship, the set of lever jaw members being located with respect to the coupling body to engage the end portion of one of the two pipes to be joined, the coupling further including a second set of first class lever jaw members having a power arm and a separate weight arm extending from an axle which forms a fulcrum, said axle having a fulcrum mounting portion extending away from the arms, a mounting hole in the coupling body receiving the fulcrum mounting portion of the set of lever jaw member of the second set of lever jaw members therein as the sole mounting to the coupling body to establish the fulcrum for rotation of each lever jaw member of the second set of lever jaw members about the fulcrum where rotation of the power arm about the fulcrum causes rotation of the weight arm about the fulcrum to an engaged position or to a disengaged position with respect to the end portion of the other pipe when received in the coupling body, the second set of lever jaw members being spaced from the set of lever jaw members and located with respect to the coupling body to engage the end portion of the other of the two pipes to be joined when the other pipe is received in the coupling body and the lever jaws of the second set of lever jaw members are rotated to an engaged position, and to disengage the end portion of such other of the two pipes when the lever jaws of the second set of lever jaw members rotate to a disengaged position.

4. A coupling for attachment to the end portion of a pipe according to Claim 3, wherein the coupling body includes at least one gasket sealing means for sealing around the ends of the pipes to be joined to prevent leakage therefrom.

5. A coupling for attachment to the end portion of a pipe according to Claim 1, wherein the coupling joins two pipes in end to end relationship, each pipe having an end portion and a shoulder in the end portion of the pipe, wherein the coupling body is adapted to closely receive the end portion of each of the two pipes to be joined in end to end relationship, the set of lever jaw members being located with respect to the coupling body to engage the shoulder in the end portion of one of the two pipes to be joined, the coupling further including a second set of first class lever jaw members having a power arm and a separate weight arm extending from an axle which forms a fulcrum, said axle having a fulcrum mounting portion extending away from the arms, a mounting hole in the coupling body receiving the fulcrum mounting portion of each set of lever jaw member of the second set of lever jaw members therein as the sole mounting to the coupling body to establish the fulcrum for rotation of each lever jaw member of the second set of lever jaw members about the fulcrum where rotation of the power arm about the fulcrum causes rotation of the weight arm about the fulcrum to an engaged position or to a disengaged position with respect to the end portion of the other pipe when received in the coupling body, the second set of lever j aw members being spaced from the set of lever jaw members and located with respect to the coupling body to engage the shoulder in the end portion of the other of the two pipes to be joined when the other pipe is received in the coupling body and the lever jaws of the second set of lever jaw members are rotated to an engaged position, and to disengage the groove of such other of the two pipes when the lever j aws of the second set of lever j aw members rotate to a disengaged position.

6. A coupling for attachment to the end portion of a pipe according to Claim 1 , wherein the coupling body includes at least one gasket sealing means for sealing around the end of the pipe to be joined to prevent leakage therefrom.

7. A coupling for attachment to the end portion of a pipe according to Claim 6, wherein the end portion of the pipe to be received in the coupling body includes an end, and additionally including a groove in the coupling body for receiving and holding a portion of the at least one gasket and positioned so that the at least one gasket held in the groove contacts the end of the pipe when received in the coupling body.

8. A coupling for attachment to the end portion of a pipe according to Claim 6, wherein the end portion of the pipe to be received in the coupling body includes a sloped end portion, and additionally including a groove in the coupling body for receiving and holding a portion of the at least one gasket, the groove having a sloped surface and being positioned so that the sloped surface of the groove is adjacent the sloped end portion to form a continuous sloped surface and the gasket held in the groove contacts the continuous sloped surface.

9. A coupling for attachment to the end portion of a pipe according to Claim 6, wherein the gasket is an inverted "U" type seal.

10. A coupling for attachment to the end portion of a pipe according to Claim 6, additionally including a groove in the coupling body for receiving and holding a portion of the at least one gasket and positioned so that the gasket held in the groove contacts the end of the pipe when received in the coupling body.

11. A coupling for attachment to the end portion of a pipe according to Claim 6, wherein the at least one gasket is a diaphragm seal.

12. A coupling for attachment to the end portion of a pipe according to Claim 1, wherein the coupling joins two pipes in end to end relationship, each pipe having an end portion, wherein the coupling body is adapted to closely receive the end portion of each of the two pipes to be joined in end to end relationship, the set of lever jaw members being located toward one end of the coupling body to engage the end portion of one of the two pipes to be joined, the coupling further including a coupling body inner end taper adjacent the other end of the coupling body; a set of jaw members slidably positioned in the inner end taper of the coupling body so that linear movement of the jaw members toward the end of the inner end taper causes movement of the jaw members radially inwardly of the coupling body against the end portion of the other of the two pipes to be joined when the other pipe is received in the coupling body; and means for securing the jaw members to the coupling body.

13. A coupling for attachment to the end portion of a pipe according to Claim 12, wherein the means for securing the jaw members to the coupling body includes linear slots through the coupling body, and bolts extending from the jaw members slidably through the slots.

14. A coupling for attachment to the end portion of a pipe, comprising: a coupling body to closely receive the end portion of the pipe to be coupled therewith; a set of first class lever jaw members having a power arm and a separate weight arm extending from a fulcrum; an axle extending into the coupling body to establish the fulcrum for rotation of each lever jaw member about the fulcrum where rotation of the power arm about the fulcrum causes rotation of the weight arm about the fulcrum to an engaged position or to a disengaged position with respect to the end portion of the pipe when the pipe is received in the coupling body; and wherein the weight arm extends from the axle within the coupling body and the power arm extends from the axle outside the coupling body so as to be operable by a user.

15. A coupling for attachment to the end portion of a pipe according to Claim 14, wherein the weight arm and the power arm both extend from the axle in approximately the same direction.

16. A coupling for attachment to the end portion of a pipe according to Claim 14, wherein the weight arm is offset from the power arm.

17. A coupling for attachment to the end portion of a pipe according to Claim 14, wherein the position of each lever jaw member is maintained by friction against movement of the lever jaw members.

18. A coupling for attachment to the end portion of a pipe according to Claim 14, wherein the coupling body includes at least one gasket sealing means for sealing around the end of the pipe to be joined to prevent leakage therefrom.

19. A coupling for attachment to the end portion of a pipe according to Claim 18, wherein the end portion of the pipe to be received in the coupling body includes an end, and additionally including a groove in the coupling body for receiving and holding a portion of the at least one gasket and positioned so that at least one gasket held in the groove contacts the end of the pipe when received in the coupling body.

20. A coupling for attachment to the end portion of a pipe according to Claim 18, wherein the end portion of the pipe to be received in the coupling body includes a sloped end portion, and additionally including a groove in the coupling body for receiving and holding a portion of the at least one gasket, the groove having a sloped surface and being positioned so that the sloped surface of the groove is adjacent the sloped end portion to form a continuous sloped surface and the gasket held in the groove contacts the continuous sloped surface.

21. A coupling for attachment to the end portion of a pipe according to Claim 18, wherein the gasket is an inverted "U" type seal.

22. A coupling for attachment to the end portion of a pipe according to Claim 18, additionally including a groove in the coupling body for receiving and holding a portion of the at least one gasket and positioned so that the gasket held in the groove contacts the end of the pipe when received in the coupling body.

23. A coupling for attachment to the end portion of a pipe, comprising: a coupling body to closely receive the end portion of the pipe to be coupled therewith; a set of first class lever jaw members having a power arm and a separate weight arm extending from a fulcrum; and means mounting each lever jaw member of the set of lever jaw members to the coupling body to establish the fulcrum for rotation of each lever jaw member about the fulcrum where rotation of the power arm about the fulcrum causes rotation of the weight arm about the fulcrum to an engaged position or to a disengaged position with respect to the end portion of the pipe when the pipe is received in the coupling body; and wherein the end portion of the pipe to be received in the coupling body includes an end and a shoulder facing away form the end, wherein the coupling body extends over the shoulder when the end portion of the pipe is inserted into the coupling body, whereby the weight arm of the set of lever jaw members engages the shoulder to secure the coupling to the pipe end portion when in engaged position.

24. A coupling for attachment to the end portion of a pipe according to Claim 23, wherein the shoulder is formed by a groove in the end portion of the pipe.

25. A coupling for attachment to the end portion of a pipe according to Claim 23, wherein the means mounting each lever jaw member and establishing the fulcrum is an axle extending into the coupling body.

26. A coupling for joining two pipes in end to end relationship, each pipe having an end portion, wherein the coupling body is adapted to closely receive the end portion of each of the two pipes to be joined in end to end relationship, comprising: a coupling body to closely receive the end portions of each of the two pipes to be joined in end to end relationship; a first set of first class lever jaw members having a power arm and a separate weight arm extending from a fulcrum; an axle extending into the coupling body to establish the fulcrum for rotation of each lever jaw member of the first set of lever jaw members about the fulcrum where rotation of the power arm about the fulcrum causes rotation of the weight arm about the fulcrum to an engaged position or to a disengaged position with respect to the end portion of one of the two pipes to be joined when the end portion of the one of two pipes to be joined is received in the coupling body; a second set of first class lever jaw members having a power arm and a separate weight arm extending from a fulcrum; an axle extending into the coupling body to establish the fulcrum for rotation of each lever jaw member of the second set of lever jaw members about the fulcrum where rotation of the power arm about the fulcrum causes rotation of the weight arm about the fulcrum to an engaged position or to a disengaged position with respect to the other end portion of the pipe when the other end portion of the pipe is received in the coupling body; wherein the respective weight arms extend from the axle within the coupling body and the respective power arms extend from the axle outside the coupling body so as to be operable by a user.

27. A coupling for joining two pipes in end to end relationship, each pipe having an end portion and a shoulder in the end portion of the pipe, wherein the coupling body is adapted to closely receive the end portion of each of the two pipes to be joined in end to end relationship, comprising: a coupling body to closely receive the end portions of each of the two pipes to be joined in end to end relationship; a first set of first class lever jaw members having a power arm and a separate weight arm extending from a fulcrum; means mounting each lever jaw member of the first set of lever jaw members to the coupling body to establish the fulcrum for rotation of each lever jaw member of the first set of lever jaw members about the fulcrum where rotation of the power arm about the fulcrum causes rotation of the weight arm about the fulcrum to an engaged position or to a disengaged position with respect to the end portion of the pipe when the pipe is received in the coupling body; a second set of first class lever jaw members having a power arm and a separate weight arm extending from a fulcrum; means mounting each lever jaw member of the second set of lever jaw members to the coupling body to establish the fulcrum for rotation of each lever jaw member of the second set of lever jaw members about the fulcrum where rotation of the power arm about the fulcrum causes rotation of the weight arm about the fulcrum to an engaged position or to a disengaged position with respect to the end portion of the pipe when the pipe is received in the coupling body; and wherein the coupling body is substantially cylindrical and of a length to extend over the circumferential shoulder of the one pipe of two pipes to be joined end-to-end and over the shoulder of the other of the two pipes to be joined, wherein the first set of lever jaws is located at one end of the body and the second set of lever jaws is located at the other end of the body.

28. A coupling for attachment to the end portion of a pipe according to Claim 27, wherein the coupling body includes a gasket sealing means around each of the ends of the pipes to be joined for sealing around the ends of the pipes to be joined to prevent leakage therefrom.

29. A coupling for attachment to the end portion of a pipe according to Claim 27, wherein the means mounting each lever jaw member and each second lever jaw member and establishing the fulcrum is an axle extending into the coupling body.

30. A coupling for attachment to the end portion of a pipe, comprising: a coupling body to closely receive the end portion of the pipe to be coupled therewith, said coupling body including an end portion extending at least partially over the pipe when the end portion of the pipe is received in the coupling body, said end portion of the coupling having an internal groove therein concentric with the pipe received in the coupling body; and at least one jaw member received in the internal groove in the coupling body in a position with respect to the pipe when received in the coupling body to secure the pipe received in the coupling body in the coupling body.

31. A coupling for attachment to the end portion of a pipe according to Claim 30, wherein the at least one jaw member received in the internal groove is movable in the internal groove between a position spaced radially from the received pipe to allow the pipe to move into or out of the coupling body and a position securing the pipe in the coupling body.

32. A coupling for attachment to the end portion of a pipe according to Claim 31 , wherein the coupling includes at least one set of first class lever jaw members having a power arm and a separate weight arm extending from a fulcrum and means mounting the set of lever jaw members to the coupling body to establish the fulcrum for rotation of each lever jaw member about the fulcrum where rotation of the power arm about the fulcrum causes rotation of the weight arm about the fulcrum, and wherein the at least one jaw member is the weight arm.

33. A coupling for attachment to the end portion of a pipe according to Claim 31 , wherein the at least one jaw member includes a camming surface and is mounted in the internal groove so that the camming surface interacts with a mating camming pin secured in the groove.

34. A coupling for attachment to the end portion of a pipe according to Claim 33, wherein the camming surface of the at least one jaw member is a camming slot in the at least one jaw member and the camming pin extends through the camming slot.

35. A coupling for attachment to the end portion of a pipe according to Claim 30, wherein the at least one jaw member is removably received in the internal groove.

36. A coupling for attachment to the end portion of a pipe according to Claim 35, wherein the internal groove opens to outside the coupling and wherein the at least one jaw member is removably slid into the internal groove to the position to secure the pipe received in the coupling body in the coupling body.