GB1604826A

GB1604826A - Pipe couplings

Info

Publication number: GB1604826A
Application number: GB3343177A
Authority: GB
Original assignee: Ashlow Steel & Eng Co
Current assignee: Ashlow Steel & Eng Co
Priority date: 1978-05-31
Filing date: 1978-05-31
Publication date: 1981-12-16

Description

(54) IMPROVEMENTS IN AND RELATING TO PIPE COUPLINGS (71) We, ASHLOW STEEL & ENGINEER ING COMPANY LIMITED, a British Company of Awl sing Road, Sheffield, (formerly of Charlotte Road, Sheffield S2 4EQ), do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- The invention relates to pipe couplings and more particularly, although not exclusively, to pipe couplings suitable for use on a marine loading arm for loading and unloading tank vessels.

According to one aspect of the invention there is provided a clamping assembly for a pipe coupling, which, in use, is arranged to be movable both axially and radially of the coupling for releasably engaging and clamping a flange of a pipe to the coupling, the clamping assembly including a clamping arm movable under control of fluid actuable ram means with a linearly movable member having wedge surfaces formed thereon interposed between the clamping arm and ram means, the arrangement being such that when the ram means is actuated to clamp said flange movement of the ram is intially transmitted to the clamping arm via a first wedge surface formed on said member to move the clamping arm generally axially towards the pipe flange and further movement of the tam means is transmitted to the clamping arm via a second wedge surface formed on said member arranged such as to reduce the movement of and hence increase e pressure exerted by the clamping arm on the pipe flange and such as to so wedge the clamping arm that with any failure of the ram means the clamping arm is retained clamped by said second wedge surface.

According to a further aspect of the inven ton There is provided a clamping assembly for a pipe coupling, which, in use, is arranged to be movable both axially and radially of the coupling for releasably engaging and damping a flange of a pipe to the coupling, the damping assembly comprising a housing assembly adapted to be pivotally mounted to a coupling body member to provide said radial movement, the housing assembly carrying a fluid actuable ram connected to control movement of a slidably mounted member having wedge surfaces formed thereon arranged to co-operate with one arm of a bell crank lever, the other arm of which forms or carries a clamping pad, the arrangement being such that when the ram is actuated to clamp said flange movement of the ram is initially transmitted to said one arm of the bell crank lever via a first of the wedge surfaces formed on the slidably mounted member to move the clamping arm generally axially towards the pipe flange and further movement of the ram is transmitted to said one arm of the bell crank lever via a second of the wedge surfaces formed on the slidably mounted member such as to reduce the movement of and hence increase the pressure exerted by the clamping arm on the pipe flange and such as to so wedge the clamping arm that with any failure of the ram the clamping arm is retained clam- ped by said second wedge surface.

The first wedge surface may be inclined at an angle of between 25 and 45 to the plane lying in the direction of movement of the movable member and the second wedge surface may be indined at an angle of less than 15 to said plane. Alternatively the wedge surfaces may be formed as an arcuate surface.

The slidably mounted member may,',,e of generally U-shaped cross-section with said wedge surfaces formed or carried an the interior surface of the base thereof and with each of the arms thereof formed with a slot into each of which depends a pip cart by said one arm of the bell craok lever, the slot having sueh shape that when the ram is actuated to release the clamping the pin following the interior surface of ti s causes the arm to pivotally ,ove the clasping arm to its retracted noa-cIamping position.

A second fluid actuable r, means nay be pivotally connected to the using rsenFly and adapted to be pivotal connected to the coupling ;body whe i::tuation ofeh ram, in use, causes said radial movement of the housing assembly.

The pivotal connection to the housing assembly may be made via a pair of links, one link being pivotally connected to the housing assembly, the other link being pivotally connected to the coupling body and both links being pivotally connected to the second fluid actuable ram.

Said clamping arm or said bell crank lever may be pivotally mounted by a removable bearing to enable emergency release of the coupling assembly, in use.

Said clamping arm or said bell crank lever may be formed in two parts which are arranged to be separable to enable emergency release of the coupling assembly, in use.

According to yet a further aspect of the invention a pipe coupling comprises a cylindrical body member having at least three and preferably four clamping assemblies as defined in any of the next preceding five paragraphs pivotally attached at equidistant points around the outer surface thereof.

According to yet a further aspect of the invention there is provided a pipe coupling as defined in the next preceding paragraph in combination with any one of a plurality of different diameter adapter plates arranged to be sealingly located between one end of the body member and the flange of a pipe to be clamped thereto, each such adapter plate having a projection located to abut and provide a stop member for locating each damp ing assembly in the radial direction in its clamping position.

Each said projection may be formed with a T-section radially outer portion and each slidable member may be formed with a slot to surround such outer portion as the ram is actuated so retaining each clamping assembly from radially outward movement The foregoing and further features of the invention may be more readily understood from the following description of some preferred embodiments thereof, by way of example, with reference to the accompanying drawings, in which: Fig. 1 is a side sectional view of part of a pipe coupling: Fig. 2 is a side elevational view, part in section, of part of a modified pipe coupling shown in its unclamped position; Fig. 3 is a side sectional view, on enlarged scale, of the Fig. 2 coupling shown in its clamped position; Fig. 4 is a sectional view showing one method of pivotally mounting a clamping arm, and Fig. 5 is a side elevational view of an alternative form of clamping arm.

Referring now to Fig. 1 of the drawings the pipe coupling comprises a cylindrical body 10 with a flange 11 attached at the forward or clamping end and a flange 12 attached at the rear end. Three or four clamping assemblies (one only shown) are pivotally attached to respective pairs of brackets 14 which are attached to body 10 and flange 12 and are equidistantly spaced circumfertially around body 10.

Each clamping assembly comprises two side plates 15 (one removed in drawing) pivotally mounted by shaft 14a and a cover plate 16. An hydraulic ram 17 is located between side plates 15 and has its piston attached to a shaft which spans the walls of a U-section slidably mounted member 19 also located between side plates 15. The internal base surface of member 19 is formed with a first wedge or cam surface 19a which is inclined at an angle B of between 25 and 45". Such surface 19a continues as a second wedge or cam surface l9b inclined at an angle of less than 15".

A shaft 20 is located to span side plates 15 adjacent the free ends thereof and pivotally mounts a bell crank lever 21, the end of one arm of which is arranged to abut surfaces 19a, l9b and the other arm 23 of which comprises the clamping arm and carries a clamping member 24 at the free end thereof.

Arm 22 carries a pin 25 which spans the arms of member 19 and locates in slots l9a formed in such arms of member 19.

A further ram 26 is pivotally connected by a shaft 27 to bracket 14 and its piston pivotally connected to a shaft 28 spanning side plates 15. Actuation of ram 26 provides movement of assembly 13 relative to body 10.

The drawing shows the coupling in position about to clamp a pipe flange 29 to an adapter plate 30 sealingly engaged with flange 11. The ram 26 has been actuated to move assembly 13 radially inwardly and the radial movement of the arm is initially controlled by the adapter plate. After the arm and the adapter plate are in contact a T-section projection 31 on adapter plate 30 is engaged by a cut-away under surface 19d of member 19. The ram 17 is now actuated to move member 19 to the left as shown in the drawing. With such movement initially arm 22 is moved upwardly by surface 19a so that clamping arm 23 is pivotted and clamping member 24 abuts pipe flange 29.

Further movement of ram 17 and hence member 19 causes arm 22 to engage surface 19b whereupon movement of arm 23 is reduced and pressure exerted by member 24 on flange 29 increased. Should the ram 17, or fluid supply thereto, fail whilst the coupling is in this clamped position the clamping arm is rigidly locked by engagement of arm 22 with surface l9b. In addition during actuation the T-section projection 31 provides a radial lock since member 19 is formed with a slot 19e which is engaged with such T-section 31 as member 19 moves.

When the pipe flange 29 is to be released ram 17 is actuated to pull back member 19 and the action of pin 25 following the contours of slots 19c ensures pivotal movement of arm 22 to retract clamping arm 23.

When member 19 has returned to the position shown in the drawing ram 26 is actuated to retract the clamping assembly by radial movement about shaft 14a.

The coupling comprises three or four clamping assemblies arranged equidistantly around body 10. The coupling can be used to clamp different diameter pipes by removing adapter plate 39 and replacing with a different such plate with similar projections 31 located according to the diameter of the pipe to be clamped. Furthermore the coupling can be used to clamp different pipe flange thicknesses by varying the thickness of the adapter plate used and/or by varying the length of clamping members 24. Preferably such members 24 are formed of Monel (Registered Trade Mark) so as to be spark resistant during the clamping action and such members are removable and replaceable.

Referring now to Figs. 2 and 3 there is shown part of a pipe coupling similar to that of Fig. 1 but shaft 28 is replaced by pin 28a pivotally attached to links 31 and 32.

Link 31 is pivotally attached at its other end to a shaft 33 spanning plates 15. Link 32 is pivotally attached at its other end to a shaft 34 spanning flanges 35 carried on member 10. Fig. 2 shows the coupling in the unclamped position and Fig. 3 shows the clamped position. This embodiment provides a more compact arrangement of ram 26.

Referring now to Fig. 4 there is shown one form of bearing for shaft 20 of the two above embodiments. The shaft 20 is in the form of a bolt which is retained by a nut 36. By providing bolt 20 should the power fail in a clamped condition the bolt 20 can be removed manually to enable emergency release of the coupling.

Fig. 5 shows an alternative form of emergency release in which arm 23 is formed in two portions 23a and 23b which are slidably engageable with one another by a dovetail joint 37. A pin 38 locks portions 23a and 23b together with a wedge 39 retaining pin 38. In an emergency release situation wedge 39 is removed and 38 removed to allow portion 23a to be removed.

In the above described embodiments, when clamping, the coupling has two functions, firstly to locate the pipe flange to be coupled and then to clamp it. Such first function is performed extremely rapidly e.g. in the order of half a second and the clamping function is performed in approximately 2 seconds.

When unclamping the unclamping function can be achieved in 2+ seconds and opening of the clamping arms in one half second.

WHAT WE CLAIM IS:- 1. A clamping assembly for a pipe coupling, which, in use, is arranged to b movable both axially and radially of the coupling for releasably engaging and clamping a flange of a pipe to the coupling, the clamping assembly including a clamping arm movable under control of fluid actuable ram means with a linearly movable member having wedge surfaces formed thereon interposed between the clamping arm and ram means, the arrangement being such that when the ram means is actuated to clamp said flange movement of the ram is initially transmitted to the clamping arm via a first wedge surface formed on said member to move the clamping arm generally axially towards the pipe flange and further movement of the ram means is transmitted to the clamping arm via a second wedge surface formed on said member arranged such as to reduce the movement of and hence increase the pressure exerted by the clamping arm on the pipe flange and such as to so wedge the clamping arm that with any failure of the ram means the clamping arm is retained clamped by said second wedge surface.

2. A clamping assembly for a pipe coupling, which, in use, is arranged to be movable both axially and radially of the coupling for releasably engaging and clamping a flange of a pipe to the coupling, the clamping assembly comprising a housing assembly adapted to be pivotally mounted to a coupling body member to provide said radial movement, the housing assembly carrying a fluid actuable ram connected to control movement of a slidably mounted member having wedge surfaces formed thereon arranged to co-operate with one arm of a bell crank lever, the other arm of which forms or carries a clamping pad, the arrangement being such that when the ram is actuated to clamp said flange movement of the ram is initially transmitted to said one arm of the bell crank lever via a first of the wedge surfaces formed on the slidably mounted member to move the clamping arm generally axially towards the pipe flange and further movement of the ram is transmitted to said one arm of the bell crank lever via a second of the wedge surfaces formed on the slidably mounted member such as to reduce the movement of and hence increase the pressure exerted by the clamping arm on the pipe flange and such as to so wedge the clamping arm that with any failure of the ram the clamping arm is retained clamped by said second wedge surface.

3. A clamping assembly as claimed in claim 1 or 2 wherein the first wedge surface is inclined at an angle of between 25 and 45" to the plane lying in the direction of movement of the movable member and the second wedge surface is inclined at an angle of less than 15 to said plane.

4. A clamping assembly as claimed in

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. ram 17 is actuated to pull back member 19 and the action of pin 25 following the contours of slots 19c ensures pivotal movement of arm 22 to retract clamping arm 23. When member 19 has returned to the position shown in the drawing ram 26 is actuated to retract the clamping assembly by radial movement about shaft 14a. The coupling comprises three or four clamping assemblies arranged equidistantly around body 10. The coupling can be used to clamp different diameter pipes by removing adapter plate 39 and replacing with a different such plate with similar projections 31 located according to the diameter of the pipe to be clamped. Furthermore the coupling can be used to clamp different pipe flange thicknesses by varying the thickness of the adapter plate used and/or by varying the length of clamping members 24. Preferably such members 24 are formed of Monel (Registered Trade Mark) so as to be spark resistant during the clamping action and such members are removable and replaceable. Referring now to Figs. 2 and 3 there is shown part of a pipe coupling similar to that of Fig. 1 but shaft 28 is replaced by pin 28a pivotally attached to links 31 and 32. Link 31 is pivotally attached at its other end to a shaft 33 spanning plates 15. Link 32 is pivotally attached at its other end to a shaft 34 spanning flanges 35 carried on member 10. Fig. 2 shows the coupling in the unclamped position and Fig. 3 shows the clamped position. This embodiment provides a more compact arrangement of ram 26. Referring now to Fig. 4 there is shown one form of bearing for shaft 20 of the two above embodiments. The shaft 20 is in the form of a bolt which is retained by a nut 36. By providing bolt 20 should the power fail in a clamped condition the bolt 20 can be removed manually to enable emergency release of the coupling. Fig. 5 shows an alternative form of emergency release in which arm 23 is formed in two portions 23a and 23b which are slidably engageable with one another by a dovetail joint 37. A pin 38 locks portions 23a and 23b together with a wedge 39 retaining pin 38. In an emergency release situation wedge 39 is removed and 38 removed to allow portion 23a to be removed. In the above described embodiments, when clamping, the coupling has two functions, firstly to locate the pipe flange to be coupled and then to clamp it. Such first function is performed extremely rapidly e.g. in the order of half a second and the clamping function is performed in approximately 2 seconds. When unclamping the unclamping function can be achieved in 2+ seconds and opening of the clamping arms in one half second. WHAT WE CLAIM IS:-

1. A clamping assembly for a pipe coupling, which, in use, is arranged to b movable both axially and radially of the coupling for releasably engaging and clamping a flange of a pipe to the coupling, the clamping assembly including a clamping arm movable under control of fluid actuable ram means with a linearly movable member having wedge surfaces formed thereon interposed between the clamping arm and ram means, the arrangement being such that when the ram means is actuated to clamp said flange movement of the ram is initially transmitted to the clamping arm via a first wedge surface formed on said member to move the clamping arm generally axially towards the pipe flange and further movement of the ram means is transmitted to the clamping arm via a second wedge surface formed on said member arranged such as to reduce the movement of and hence increase the pressure exerted by the clamping arm on the pipe flange and such as to so wedge the clamping arm that with any failure of the ram means the clamping arm is retained clamped by said second wedge surface.

4. A clamping assembly as claimed in

claim 1 or 2 wherein said first and second wedge surfaces are formed as an arcuate surface.

5. A clamping assembly as claimed in claim 2, or claim 2 and 3 or 4 wherein the slidably mounted member is of generally U-shaped cross-section with said wedge surfaces formed or carried on the interior surface of the base thereof and with each of the arms thereof formed with a slot into each of which depends a pin carried by said one arm of the bell crank lever, the slot having such shape that when the ram is actuated to release the clamping the pin following the interior surface of the slots causes the arm to pivotally move the clamping arm to its retracted nonclamping position.

6. A clamping assembly as claimed in claim 2 or claim 2 and 3, 4 or 5 wherein a second fluid actuable ram means is pivotally connected to the housing assembly and adapted to be pivotally connected to the coupling body whereby actuation of such ram, in use, causes said radial movement of the housing assembly.

7. A clamping assembly as claimed in claim 6 wherein the pivotal connection to the housing assembly is made via a pair of links, one link being pivotally connected to the housing assembly, the other link being pivotally connected to the coupling body and both links being pivotally connected to the second fluid actuable ram.

8. A clamping assembly as claimed in any preceding claim wherein said clamping arm or said bell crank lever is pivotally mounted by a removable bearing to enable emergency release of the coupling assembly, in use.

9. A clamping assembly as claimed in any of claims 1 to 7 inclusive, wherein said clamping arm or said bell crank lever is formed in two parts which are arranged to be separable to enable emergency release of the coupling assembly, in use.

10. A pipe coupling comprising a cylindrical body member having at least three clamping assemblies as claimed in any preceding claim attached at equidistant points around the outer surface thereof.

11. A pipe coupling as claimed in claim 10 in combination with any one of a plurality of different diameter adapter plates arranged to be sealingly located between one end of the body member and the flange of a pipe to be clamped thereto, each such adapter plate having a projection located to abut and provide a stop member for locating each clamping assembly in the radial direction in its clamping position.

12. A pipe coupling as claimed in claim 11 wherein each said projection is formed with a T-section radially outer portion and each slidable member may be formed with a slot to surround such outer portion as the ram is actuated so retaining each clamping assembly from radially outward movement.

13. A pipe coupling substantially as hereinbefore described with reference to Fig. 1 of the accompanying drawings.

14. A pipe coupling substantially as hereinbefore described with reference to Figs. 2 and 3 of the accompanying drawings.

15. A pipe coupling as claimed in claim 14 modified substantially as hereinbefore described with reference to Fig. 4.

16. A pipe coupling as claimed in claim 13 or 14 modified substantially as herein before described with reference to Fig. 5