GB2286029A - Locking mechanism for quick release pipe coupling - Google Patents

Abstract

A quick release pipe connector for use in oil and gas wells includes a hollow male member 1 adapted to be rotatably received in a female hollow members 2 by means of asymmetric shoulders 9 provided on the male member 1 and corresponding asymmetric recesses 10 in the female member 2. The male and female members 1, 2 are locked against relative rotation by a locking sleeve 3 having octagonal inner and outer faces. The sleeve 3 is slidably received in an octagonal recess in the female member 2 and in the locked position engages with an octagonal profile 11 on the male member 1. The octagonal profile 11 on the male member 1 and the inner octagonal face of the sleeve 3 both have one face of a different size to the rest so that the male member 1 will only fit into the sleeve 3 in one of the eight possible configurations. A tool 8 for releasing the sleeve 3 from the octagonal profile 11 is also disclosed. <IMAGE>

Description

LOCKING MECHANISM Field of the Invention The invention relates to locking mechanisms for quick release connectors. It is particularly applicable, but in no way limited to hollow quick release connectors.

Background to the Invention Tools can be lowered down or raised from oil and gas wells by jointed tubulars e.g drill pipe or continuous "coiled" tubing or by wireline. Tools such as hydraulic motors with drilling cutters are commonly deployed by means of tubing. Flow of fluid through the tubing actuates the tools and thus any connector must allow the unrestricted passage of a fluid. In addition, it is common to switch the function of a tool by dropping a ball. The connecting tool must thus also permit the passage of a sufficiently large ball.

Releasable tool connectors are also common in the related oil field technology of wireline service. Here the tools do not require flow and are deployed on a single strand or braided steel cable.

The most common tubing-deployed connector systems in use are hollow screw threads. These require valuable time to screw together and in addition they must be assembled to the correct torque to prevent accidental loosening off and loss down-hole. When produced in durable stainless steel alloys, the threads are prone to instantaneous seizure and subsequent damage on movement called galling, due to the high stresses imposed on the material in intimate contact within the threads.

One type of hollow quick release tool is known and is illustrated in Figure 1.

The tool transfers axial load by a pair of interlocking shoulders. Torque loads are transferred by three latches which all have to be withdrawn simultaneously in order to mutually rotate the tool parts and so dissemble the tool. This arrangement has a number of inherent disadvantages. Firstly, disassembly is a multi-handed operation since all three triggers need to be depressed simultaneously. Secondly, debris can get lodged behind the release trigger preventing it being depressed.

It is the object of the present invention to overcome these disadvantages and to provide a simple, inexpensive yet robust locking mechanism suitable for use on a wide variety of quick release connectors.

Summarv of the Invention According to a first aspect of the present invention, in its broadest sense, there is provided a quick release hollow connector comprising the following combination of features: (i) a male member having a tubular hollow body; (ii) a female member having a hollow tubular body and being adapted at one end to receive the male member; (iii) engagement means for co-operatively engaging the male and female members; (iv) a locking mechanism for releasably securing the male member and the female member in co-operative engagement; characterised in that the locking member comprises a polygonal-shaped sleeve adapted to co-operatively engage with a correspondingly polygonalshaped portion on one or both of the said members, said sleeve being movable between a first, engaged position wherein the male and female members are locked together and a second, disengaged position in which the male and female members are free to rotate with respect to each other.

Preferably the polygonal-shaped sleeve incorporates polygonal faces on both the exterior and interior surfaces of the sleeve, said sleeve being adapted to fit within a correspondingly shaped polygonal aperture in the female member, the sleeve and aperture being so sized and shaped that the sleeve cannot rotate within the said aperture.

Preferably the polygonal sleeve can engage with the male and/or female members in only one configuration such that in use the male and female members always co-operatively engage in the same spatial relationship.

Preferably the locking mechanism incorporates a biasing means to resiliently bias the sleeve into the so-called engaged position.

Preferably the male member incorporates within a portion of its circumference a series of shoulders adapted to co-operatively engage with corresponding shoulders in the female member.

In a further embodiment of the present invention there is provided a locking mechanism for a quick release joint of the type in question in which a female and a male member co-operatively engage comprising a polygonal-shaped sleeve adapted to co-operatively engage with a correspondingly polygonalshaped portion on one or both of the said members, said sleeve being movable in use between a first, engaged position wherein the male and female members are locked together and a second, disengaged position in which the male and female members are free to rotate with respect to each other.

Preferably the polygonal-shaped sleeve incorporates polygonal faces on both the exterior and interior surfaces of the sleeve, said sleeve being adapted to fit within a correspondingly shaped polygonal aperture in the female member, the sleeve and aperture being so sized and shaped that the sleeve Preferably the polygonal sleeve can engage with the male and/or female members in only one configuration such that the male and female members always co-operatively engage in the same spatial relationship.

Preferably the locking mechanism incorporates a biasing means to resiliently bias the sleeve into the so-called engaged position.

Brief Description of the Drawings Preferred embodiments of the present invention will now be more particularly described by way of example, with reference to the accompanying drawings wherein: Figure 1 shows a hollow quick release connector according to the prior art; Figure 2 shows cut away perspective and cross-sectional diagrams of a quick release connector according to a first embodiment of the present invention; Figure 3 shows two cross-sections of a sleeve; Figure 4 shows a coil spring biasing means; Figure 5 shows the male end of a male connector; Figures 6 to 8 show various cross-sectional views of the male member illustrated in Figure 5; Figures 9 to 12 show various cross-sectional views of a female member; Figure 13 shows an end view of the female connector illustrated in Figures 9 to 12.

Description of the Preferred Embodiments The present embodiments represent currently the best ways known to the The present embodiments represent currently the best ways known to the applicant of putting the invention into practice. But they are not the only ways in which this could be achieved. They are illustrated, and will now be described, by way of example only.

Figure 2 illustrates the general arrangement of a locking mechanism according to the present invention applied to a hollow quick release connector. A male member 1 is adapted to fit into a female member 2. The portion of the male member which fits within the female member is substantially circular in cross-section and incorporates into its external surface a series of longitudinally spaced radial flanges or shoulders 9. These shoulders do not extend to the same depth around the whole circumference of the member 1, being instead asymmetrically disposed about the longitudinal axis. This is more clearly shown in Figures 5,7 and 8.

A corresponding series of recesses 10, also termed shoulders, are formed around the internal circumference of the female member 1. The bilateral arrangement of shoulders means that in a particular configuration the male member can be fully inserted into the female member. Rotation of the male member through 90" with respect to the female member fully engaging the two sets of shoulders to provide maximum tensile strength. It is the function of the locking mechanism to hold the two members in this so-called "locked" position, to provide torsional strength and to prevent the connector separating inadvertently.

In this example the locking mechanism comprises an anti-rotational sleeve 3, spring 4 and octagonal-shaped section 11 on the male member 1. A release tool 8 is also provided. The sleeve 3 is illustrated in Figure 3. The external and internal faces of the sleeve are octagonal and the sleeve fits within an octagonal-shaped housing or recess in the female member as shown in Figure 2b. If required, it can be held in place with a retaining ring 5. Thus the sleeve cannot rotate within its housing but can be moved backwards and forwards along the longitudinal axis against the force of spring 4. This movement is achieved by the release tool 8 which is in effect a part of modified circlip pliers. One point of the tool engages in a first recess 12 in the body 2, the other point engages in a second recess 14 in the sleeve itself. A slot 13 extending through the wall of the female member 2 gives access to the recess 14 and allows movement of the sleeve within pre-determined limits.

The octagonal shape 11 and internal octagonal sleeve surface both have one face of a different size to the rest. This means that the male member 2 will only fit into the sleeve in one of the eight possible configurations. In assembly for use the arrow 30 on the male member 1 (see Figure 5) is aligned with the slot 13 in the female member 2. In this position the male 14 can be fully inserted into the female portion but the octagon 11 cannot fit into the sleeve.

The male portion is pushed fully into the female portion against the pressure of the spring 4 and the two members rotated through 90C with respect to each other. The octagon 11 and sleeve surface 20 now correspond and the sleeve springs back to its original position, locking the two members as it does so.

The release is a simply matter of depressing spring 4 with tool 8 whilst rotating the male portion in relation to the female. Once the arrow and slot line up the two parts of the coupling come apart because the shoulders 9 and 10 no longer engage.

A fluid-tight seal between the members 1, 2 is achieved by using a double ring seal 6, 7.

Certain advantages of this locking system will now be apparent.

(a) The mechanism is annular and thus spreads the load around the circumference of each part of the coupling. It is in effect equivalent to having eight separate triggers in the prior art and being able to depress all eight simultaneously.

(b) Although there is a slot 13 in the body of the coupling this is automatically covered at all times with a sleeve, preventing ingress of debris.

No additional cover is required unlike the prior art.

(c) This arrangement provides for a strong spring 4 coupled with a low mass sleeve 3, the ideal combination if accidental release by jarring is to be avoided.

(d) A positive 90C rotation is required to lock the components together.

(e) Only one mechanism needs to be activated to achieve release.

(f) For the same materials of construction the ratio of outside diameter of coupling to inside diameter of the hole through the coupling is significantly greater than in the prior art. Typical figures are, 2.13/0.88 in the present invention compared with 2.25/0.5 in the prior art (see Figure 1).

Although developed for hollow connectors, this type of locking mechanism is equally applicable to all forms of quick release couplings, referred to in this context as couplings of the type in question, including those for wireline use.

The multiple shoulder version illustrated needs to be made with extreme accuracy in order to achieve proper load sharing between the shoulders without them deforming. This is best achieved using a computer numerical controlled machining centre.

Claims (11)

CLAIMS:

1. A quick release hollow connector comprising the following combination of features: (i) a male member having a tubular hollow body; (ii) a female member having a hollow tubular body and being adapted at one end to receive the male member; (iii) engagement means for co-operatively engaging the male and female members; (iv) a locking mechanism for releasably securing the male member and the female member in co-operative engagement; characterised in that the locking member comprises a polygonal-shaped sleeve adapted to co-operatively engage with a correspondingly polygonalshaped portion on one or both of the said members, said sleeve being movable between a first, engaged position wherein the male and female members are locked together and a second, disengaged position in which the male and female members are free to rotate with respect to each other.

2. A quick release hollow connector as claimed in Claim 1 wherein the polygonal-shaped sleeve incorporates polygonal faces on both the exterior and interior surfaces of the sleeve, said sleeve being adapted to fit within a correspondingly shaped polygonal aperture in the female member, the sleeve and aperture being so sized and shaped that the sleeve cannot rotate within the said aperture.

3. A quick release hollow connector as claimed in Claim 2 wherein the polygonal sleeve can engage with the male and/or female members in only one configuration such that in use the male and female members always cooperatively engage in the same spatial relationship.

4. A quick release hollow connector according to any preceding Claim wherein the locking mechanism incorporates a biasing means to resiliently bias the sleeve into the so-called engaged position.

5. A quick release hollow connector according to any preceding Claim wherein the male member incorporates within a portion of its circumference a series of shoulders adapted to co-operatively engage with corresponding shoulders in the female member.

6. A quick release hollow connector substantially as herein described with reference to and as illustrated in any combination of Figures 2 to 13.

7. A locking mechanism for a quick release joint in which a female and a male member co-operatively engage comprising a polygonal-shaped sleeve adapted to co-operatively engage with a correspondingly polygonal-shaped portion on one or both of the said members, said sleeve being movable in use between a first, engaged position wherein the male and female members are locked together and a second, disengaged position in which the male and female members are free to rotate with respect to each other.

8. A locking mechanism as claimed in Claim 7 wherein the polygonalshaped sleeve incorporates polygonal faces on both the exterior and interior surfaces of the sleeve, said sleeve being adapted to fit within a correspondingly shaped polygonal aperture in the female member, the sleeve and aperture being so sized and shaped that the sleeve cannot rotate within the aperture.

9. A locking mechanism according to Claim 7 or Claim 8 wherein the polygonal sleeve can engage with the male and/or female members in only one configuration such that the male and female members always cooperatively engage in the same spatial relationship.

10. A locking mechanism according to any of Claims 7 to 9 wherein the locking mechanism incorporates a biasing means to resiliently bias the sleeve into the so-called engaged position.

11. A locking mechanism substantially as herein described with reference to and as illustrated in any combination of Figures 2 to 13