GB2101264A - Pinned coupling - Google Patents

Abstract

A pinned coupling comprises first and second members (16, 17) having a passage (19) extending there through, in which passage (19) a load bearing pin (25) is received, the pin (25) being adapted to be retained in the passage (19) by a retaining means comprising a retaining element (28) at least partially received within the first portion of the passage (19) to retain the pin (25) and at least one locking member (40) extending through an opening (30) in said first member (16) which intersects with said passage (19), the locking member (40) engaging the retaining element (28) to prevent the pin (25) from moving through the first portion of the passage (19). <IMAGE>

Description

SPECIFICATION Pinned coupling DESCRIPTION OF INVENTION This invention relates to a pinned coupling, hereinafter referred to as of the type specified, having first and second members, a passage (as herein defined) extending through and between the first and second members, in which passage a load bearing pin is received, the pin being adapted to be retained in the passage.

By "pin" we mean an elongate member which may be of circular or non-circular configuration, solid or hollow. By the term "passage" we mean a passage having a first portion comprising a bore or opening in the first member, the second portion comprising a bore or opening in the second member, the third portion extending through a space between the first and second members in which space the link of a chain or other loop may be received, the third portion of the passage extending through the loop.

The bore or opening in the second member may be blind. i.e. closed at the outer end thereof.

A disadvantage encountered with known pinned couplings is that the coupling may be tampered with and the load bearing pin removed and perhaps lost. The pin may then be replaced with an inferior member with less physical strength, which member is liable to break when the link is put under load.

Previously, the load bearing pin has been retained in engagement in the passage by means of a locking pin or pins which extend transversely of the load bearing pin. However it has been found that such locking pins may be too easily removed.

Accordingly it is an object of the present invention to provide a new or improved pinned coupling which overcomes or reduces the above mentioned disadvantage.

According to a first aspect of the present invention, we provide a pinned coupling of the type specified, comprising a retaining means for retaining the pin in the passage, the retaining means comprising a retaining element, at least partially received within the first portion of the passage to retain the pin, and at least one locking member extending through an opening in said first member, which intersects with said passage, the locking member engaging the retaining element to prevent the pin from moving through the first portion of the passage.

The retaining element is preferably integral with or fixed to the pin but may be a separate member.

Thus it is not possible for the load bearing pin to be removed from the passage without removing the locking member and the retaining element where separate from the pin, and it is thus difficult for any person to tamper with the coupling.

In one embodiment, the locking member may comprise a roll pin, split pin, or solid rod, or any other member which is an interference fit with a formation of the retaining element such as an opening and/or the opening in the first member, thereby making removal of the locking member and hence removal of the retaining element and hence the pin difficult, if not impossible, without drilling for example.

Where the retaining element is a separate member, preferably, the load bearing pin is of such length that an outer part of the first portion of the passage is not occupied by the pin but by the retaining element which is engaged by the locking member. Said retaining element may have an opening aligned with the opening in the first member, the locking member extending through the opening in the first member into an opening in the retaining element.

Preferably, the retaining element comprises a solid disc insert, having a cylindrical peripheral wall, the formation of the insert being provided in the peripheral wall. Whether the retaining element is separate from the pin or not, the opening in the first member may be larger than the locking member and the opening in the retaining element, so that the locking member is an interference fit with the opening in the retaining element only.

Thus, inserting the locking member is facilitated as the locking member can be retained in the opening in the first member whilst being driven into the opening in the retaining element.

Further, two openings may be provided in the retaining element, in opposite positions and two openings being provided in the first member, each of the openings in the retaining element being aligned with one of the openings in the first member, a locking member being received in each pair of aligned openings.

The two openings in the retaining element may communicate so that the locking members may be removed by punching, for example, one locking member from one of said two openings into the other opening to abut and thereby force the other locking member from said other opening, and then to punch said one locking member from the other opening.

Preferably, however the two openings are separated by a core of the retaining element so that it is necessary to drill or otherwise remove the core to enable the locking members to be removed as previously described, the one locking member being punched through the space no longer occupied by the core, into said other opening.

In another embodiment, the retaining element comprises a separate rivet engaging element to engage the pin, and the locking member comprises a rivet to engage the rivet engaging element.

Again, preferably the load bearing pin is of such length that when it is received in the passage, an outer part of the first portion of the passage is not occupied by the pin, and the rivet extends into said outer part behind the pin, the rivet engagement element being inserted in the unoccupied outer part of the first portion of the passage and being engaged by the rivet to hold the pin.

Said element may have an opening aligned with the opening in the first member, the rivet extending through the opening in said first member into the opening in the rivet engagement element.

The rivet engaging element may have a recess therein which communicates with said opening in the element into which recess the end of the rivet extends, to permit the end of the rivet to be expanded when inserted, to a diameter greater than the diameter of the opening in the rivet engaging element.

The opening in the first member in which the rivet is received, may be countersunk at the outer end thereof, to permit the rivet head to lie flush or substantially flush with the surface of the first member.

Preferably, the rivet engaging element comprises a cup-shaped insert, having a cylindrical peripheral wall closed by an end cap, the opening being provided in the peripheral wall.

The recess into which the end of the rivet extends may thus comprise the interior of the insert.

Preferably, the cup-shaped insert is received in the outer end of the first portion of the passage with the open end of the insert lying adjacent to the end of the pin. Thus access cannot be gained to the rivet from the outer part of the passage. The insert may be made as a pressing in mild steel, or low carbon steel to increase the wear resistance of the insert, although the insert may be made as a turning or casting if required.

Alternatively, the rivet engagement element may comprise a hollow pin-like element, the rivet being received in an end of the pin.

Further alternatively, the rivet engaging element may be solid and have a recess bored therein, which recess communicates with the opening in the element, to permit the end of the rivet to be expanded, and the open end of the recess may lie adjacent the end of the pin.

The element may be a disc-like element and may have an opening extending transversely therethrough, the rivet extending through the opening.

If desired, a closure means may be provided to close the end of the bore particularly where the rivet engaging element is disc-like and a tamper proof facility is required.

Preferably. the rivet is a blind rivet, the end of the rivet expanding within the opening or recess of the rivet engaging element.

Two rivets in corresponding spaced openings in the first member may be provided if required, or more than two.

The load bearing pin may be non-circular and the passage circular, whereby the pin may rotate in the passage as a loop in the third part of the passage through which the pin extends, pivots.

Where the retaining element is integral or fixed to the pin, the opening or openings in the element may comprise a slot or slots which enable the non-circular pin to rotate in the passage through an angle restricted by the extent of the slots.

When the slot comprises a circumferential groove the pin may rotate without restriction.

In any of the above described embodiments, the locking member or members are preferably made of steel, although they may be made of copper/nickel alloy which provides a corrosion resistant facility. The retaining element may be stronger than the locking member or members so that if the coupling is exposed to excess load, the or each locking member shears before the element fails.

The second portion of the passage in the second member may be blind, i.e. closed, and only the end of the load bearing pin in the first portion of the passage requiring retaining means.

Alternatively, the second portion of the passage in the second member may be open and thus extend through the second member in which case further retaining means such as described above or otherwise may be provided to retain the pin in the second portion of the passage.

The retaining element may lie closely adjacent the walls of the first portion of the passage, to close the passage, and thereby prevent dirt from entering the passage, and to prevent tampering with the locking member, from the outer part of the passage.

The coupling may comprise a clevis end of a hook, reevable link, coupler, clutch or any other similar load bearing component to which it is desired to attach a member, for example, the link of a chain or other loop.

According to a second aspect of the invention, we provide a method of connecting a link of a chain or other loop to a load bearing member comprising a pinned coupling of the type specified, comprising the steps of locating the loop in a space between first and second members of the pinned coupling, inserting a load bearing pin into a passage (as herein defined) which extends through and between said first and second members, to entrap the loop in said space, engaging at least one locking member in an opening in said first member which intersects with said passage to engage a retaining element received therein.

Where the retaining element is separate from the pin, the method may include the step of inserting a retaining element in said passage behind the pin to retain the pin in the passage prior to engaging the locking member.

Where the retaining element comprises a rivet engaging element and the locking member a rivet, the method may include the step of forming an opening in the rivet engaging element, after the rivet engaging element has been inserted in the outer part of the passage.

One example of the invention will now be described with reference to the accompanying drawings, in which: FIGURE 1 is a perspective exploded view of a first embodiment of the invention comprising a clevis having a pinned coupling to which clevis a chain may be coupled; FIGURE 2 is a plan fragmentary sectional view of the clevis of Figure 1 showing the pinned coupling at one stage during assembly with a link of a chain coupled thereto; FIGURE 3 is a view similar to that shown in Figure 2 showing an assembled coupling at one stage during disassembly; FIGURE 4 is a view similar to that of Figures 2 and 3 showing the coupling at a further stage of disassembly; FIGURE 5 is a side view of a second embodiment of the invention comprising a hook having a pinned coupling to which hook a chain is coupled;; FIGURE 6 is a fragmentary sectional view to an enlarged scale of the hook of Figure 5 showing the pinned coupling; FIGURE 7 is a section on the line A-A of Figure 5; FIGURE 8 is a fragmentary view of part of a clevis similar to Figure 1 showing a similar embodiment but having an alternative retaining element.

Referring to Figures 1 to 7 of the drawings, there is shown a clevis 10 having a pinned coupling for attaching a loop comprising a link 13 of a chain thereto.

The coupling 11 has first and second members 1 6 and 1 7 respectively, connected by a base part 18, the first member 1 6 having a cylindrical bore 19 which extends therethrough, which bore 19 comprises a first portion of a passage The second member 1 7 has a blind cylindrical opening 21 comprising a second portion of the passage, and a third portion of the passage being provided by a space 22 between the first and second members 1 6, 1 7, the space 22 extending through the link 13 of the chain.

Received in the passage is a load bearing pin 25 of non-circular configuration (not shown in the passage in Figure 1), which pin 25 passes through the link 13 of the chain.

The outer part 26 of the bore 1 9 in the first member 1 6 is not occupied by the pin 25 but by a disc-shaped insert 28 comprising a retaining element. The insert 28 comprises a cylindrical peripheral wall 29 which in use, lies closely adjacent the wall of the passage to restrain the ingress of dirt. The insert 28 is made of mild steel and is fabricated in any convenient way.

Further provided in member 16 are a pair of openings 30 which communicate with the passage 20 and are aligned with correspondingly arranged openings 31 in the insert 28. The openings 31 are of slightly smaller diameter than the openings 30 for a reason hereinafter described.

Locking members comprising roll pins 34, 35 made of steel are received in the openings 30 and extend into the aligned openings 31 in the insert 28, the pins 34, 35 expanding to provide an interference fit with the walls of the openings 31, due to their intrinsic resilience. The outer ends 40 of each of the pins 34, 35 are chamfered and lie flush with the surface 14 of the member 1 6. The pins 34, 35 when engaged with the openings 31 of inserts 28 are thus extremely difficult to remove from the openings 30, from the outside thus providing a tamper proof connection. It will be noted that the diameter of passages 30 is greater than the expanded diameter of the pins 34, 35.

Thus, the pins 34, 35 may be easily received in the openings 30 and held whilst being driven into the smaller diameter openings 31 of the retaining element 28 with a suitable driving tool such as a hammer or punch. Thus the pin 35 is retained in the passage by the blind opening 21, and the insert 28 which is in turn held by pins 34, 35.

The insert 28 is made of sufficient strength that if the coupling 11 is placed under excess stress, the pins 34, 35 will fail first.

Many modifications and alterations are of course possible, for example the second portion of the passage in the second member 1 7 may be open and an insert 28 and locking members such as pins 34, 35 used as described above, to retain the pin 20 at that end. Further, other configurations of retaining element 28 are possible, for example the retaining element may be partially hollow.

Although two pins 34, 35 have been described as being used, one or more than two may be provided if required, although having two aligned pins provides the following advantages when it is desired to remove the load bearing pin 25 from the passage.

Referring in particular to Figure 2, it can be seen that the openings 31 in the retaining element 28 are separated by a core C of retaining element material. If the core C is drilled out with a drill D to provide a space B such as shown in Figure 3 which connects the two aligned openings 31 , then the pins 34, 35 may be removed by using a suitable punching tool P shown in Figure 4 the operative part of which is of smaller diameter than openings 30 or 31, to punch pin 34 through the space B made by drilling, into the opposite passage 31, where it abuts and thereby forces the other pin 35 out of the opening 31. By continued punching, the pin 34 may also be removed from the opening 31 once occupied by pin 35.The retaining element 28 may thus be removed enabling the load bearing pin 25 also to be removed and thus for the link 13 of the chain to be released from the space between the first and second members.

It can be seen that the retaining element 28 has a slight indentation don the end 36 thereof prior to drilling which facilitates initially aligning the drill D when it is desired to remove the load bearing pin 25. Further, the preferred drill size may be marked on the end 36 of the element 28 if desired.

A further feature of the invention is that the insert 28 has a bevelled inner face 37 which contacts the square end 38 of the load bearing pin 25 so that the load bearing pin 25 may rotate in passage 20 without imposing a rotational force on the insert 28 which could shear the locking members 34, 35.

Further, the end of the pin 25 which is received in the blind bore 21 is tapered, as shown at 42, the tapered part 42 engaging the round end 43 of the bore 21.

Thus if desired, after removing the retaining elements 28 as hereinbefore described, by drilling, it is desired to utilise a conventional coupling rather than the tamper proof coupling described, the pin 25 may be reversed so that the end 38 is received in the blind bore 21. As this end is not tapered, the tapered end 42 will lie further to the left than the left untapered end of the pin as shown in Figures 1 to 4 and thus a conventional locking pin received in the opening 31 will engage behind the tapered end 42 of the pin 25, preventing the pin 25 from moving longitudinally in the passage.

Although this embodiment of the invention has been described with reference to a chain, the invention may be used to connect any other loop to the clevis 10. The clevis 10 may comprise the end of a hook, or like member to which it is desired to attach a loop and provide a tamper proof connection.

Referring to Figures 5 to 7 of the drawings, there is shown a hook 10' having a pinned coupling 11' for attaching a loop comprising a link 13' of a chain 14' thereto, the pinned coupling 11' being shown in detail in Figure 5 and Figure 6.

The coupling 11' has first 16' and second 17' members connected by a base part 18'. The first member 16' has a cylindrical bore 19' which extends therethrough, which bore 19' comprises a first portion of a passage 20'.

The second member 17' has a blind cylindrical opening 21' comprising a second portion of passage 20', and a third portion of the passage 20' is provided by a space 22' between the first 16' and second 17' members. which space 22' extends through the link 13' of chain 14'.

Received in the passage 20 is a load bearing pin 25' of non-circular configuration, which pin configuration corresponds to the shape of and passes through the link 13' of the chain 14'. Thus, as the link 13' pivots in space 22', the pin 25' will rotate therewith in the passage 20'.

The outer part 26' of the bore 19' in the first member 16', is not occupied by the pin 25', but by a cup-shaped insert 28' comprising a rivet engaging element which is received therein. The insert comprises a cylindrical peripheral wall 28a' which is closely adjacent the wall of the passage 20', and an end cap 28b' which closes the insert.

The insert is made as a pressing in mild steel but if desired the insert 28' may be fabricated by brazing a disc onto a tube but may be made in any other convenient way.

The open end 29' of the insert 28' lies adjacent to the end of the pin 25'.

Further provided in member 16' is a pair of openings 30' which communicate with the passage 20', and are aligned with correspondingly arranged openings 31' in the insert 28'.

The outer ends 33' of the openings 30' are counter-sunk. Rivets 34', 35' made of copper/nickel alloy which provides corrosion resistance, are received in the openings 30' and extend into the interior recess of the insert 28' through the openings 31', the inner ends 39' of the rivets 34', 35' being permitted to expand to a diameter greater than that of the openings 31', due to the interior recess, and the head 40' of the rivets 34', 35' lying in the countersunk end 33', flush with the surface of the member 16'.

The rivets 34', 35' are of well known type having an inner mandrel 41' which is actuated by a riveting tool to cause the inner ends 39' of the rivets 34', 35' to expand in the passage 20', as shown, to grip the insert 28' and thereby secure the insert 28' in the passage 20'.

Thus the pin 25' is retained in the passage 20' by the blind end 21', the end surface 29a' of the peripheral wall 28a' of the insert 28', and the rivets 34', 35'. The end cap 28b' of the insert 28' prevents the rivets 34', 35' being tampered with from the outer part 29 of the passage 20' and also restrains the ingress of dirt.

The insert is made of sufficient strength that if the rivets 34', 35' are placed under excess stress, the rivets will fail first.

Many modifications and alterations are possible. For example, the bore in the second member 17' may be open and rivets and insert or rivet engaging element, used as described above, to retain the pin 20' at that end.

Other configurations of rivet engaging element are possible, for example the rivet engaging element may be solid and may have a recess comprising a bore therein which communicates with openings 30',31 in the first and second members 1 6', 1 7' to permit the rivets 34', 35' to expand at their inner ends 39', or the rivet engaging element may comprise a hollow pin, the rivets 34', 35' being received in the ends of the pin and radial openings may be provided in the pin to permit expansion of the rivet over a limited circumferential extent. Further alternatively, the rivet engaging element may comprise a disc positioned between the rivets and the end of the pin.

Where the rivet is able to expand freely radially when upset, such as in the end of the cup-shape insert illustrated, a greater resistance to removal is achieved than when no, or only free expansion in a limited circumferential region, is permitted.

Although two rivets have been described as being used, one or more than two may be provided if required. A recess such as the interior of the insert 28' need not be provided, in which case the rivet or rivets will merely engage the walis of the openings 31'.

In place of the two short rivets 34, 35 described, if desired a single long rivet which extends through the passage through openings 30, could alternatively be provided, although it has been found that such a long rivet at least if of the type upset by axial compressive loading, could buckle in passage 20. Thus we prefer to use two short rivets, 34, 35 as shown, which preferably engage a cap insert 28 as shown, although a long blind rivet which would be strengthened or constructed to resist buckling due to the mode of upsetting, could be used if desired.

Although the first embodiment has been described with reference to a clevis comprising the end of a hook to which a chain is connected, and the second embodiment of the invention has been described as a chain 14 and hook 10, the invention may be applied to any other member having a pinned coupling such as a reevable link, coupler, clutch or any other member to which it is desired to attach a member, for example a chain or any other loop such as the loop provided at the end of a steel cable or rope or the like.

For example, the pinned coupling may comprise an open-topped box-like connector within which a chain link or other loop is received, through which, and retained in opposite walls thereof, a load bearing pin extends the pin being retained by a rivet or rivets as hereinbefore described.

Figure 8 shows part of a coupling similar to that shown in Figure 1 and thus similar parts are indicated by the same reference numerals. The only difference is that instead of providing a separate retaining element 128 separate from the pin 25, the retaining element 128 is made integral with the pin 25 although it may be attached, for example by welding, if desired.

The retaining element 128 is round whereas the pin 25 is non-circular. Instead of providing an opening 31 in the retaining element 128 of circular configuration, a circumferential groove 131 is provided to enable the pin 25 to rotate in the passage without restraint. Of course if some restriction of the extent of rotation is required a slot or slots of appropriate part circumferential extent could be provided.

Claims (43)

1. A pinned coupling of the type specified, comprising a retaining means for retaining the pin in the passage, the retaining means comprising a retaining element, at least partially received within the first portion of the passage to retain the pin, and at least one locking member extending through an opening in said first member, which intersects with said passage, the locking member engaging the retaining element to prevent the pin from moving through the first portion of the passage.

2. A pinned coupling according to claim 1 wherein the retaining element is integral with or fixed to the pin.

3. A pinned coupling according to claim 1 wherein the retaining element is a separate member to the pin.

4. A pinned coupling according to any one of claims 1 to 3 wherein the locking member is an interference fit with a formation of the retaining element and/or the opening in the first member.

5. A pinned coupling according to claim 3 or claim 4 where dependent on claim 3 wherein the load bearing pin is of such length that an outer part of the first portion of the passage is not occupied by the pin but by the retaining element which is engaged by the locking member.

6. A pinned coupling according to claim 5 wherein said formation of the retaining element comprises an opening aligned with the opening in the first member, the locking member extending through the opening in the first member into an opening in the retaining element.

7. A pinned coupling according to any one of claims 3 to 6 wherein the retaining element comprises a solid disc insert, having a cylindrical peripheral wall, the formation of the insert being provided in the peripheral wall.

8. A pinned coupling according to any one of the preceding claims wherein the opening in the first member is larger than the locking member and the opening in the retaining element, so that the locking member is an interference fit with the opening in the retaining element only.

9. A pinned coupling according to claims 6 to 8 where dependent on claim 6 wherein two openings are provided in the retaining element, in opposite positions and two openings being provided in the first member, each of the openings in the retaining element being aligned with one of the openings in the first member, a locking member being received in each pair of aligned openings.

10. A pinned coupling according to claim 9 wherein the two openings in the retaining element communicate so that the locking members may be removed by moving one locking member from one of said two openings into the other opening to abut and thereby force the other locking member from said other opening, and then removing said one locking member from the other opening.

11. A pinned coupling according to claim 9 wherein the two openings are separated by a core of the retaining element so that it is necessary to remove the core to enable the locking members to be removed by moving one locking member from one of said two openings, through the space no longer occupied by the core, into the other opening to abut and thereby force the other locking member from said other opening, and then removing said one locking member from the other opening.

12. A pinned coupling according to claim 1 wherein the retaining element comprises a separate rivet engaging element to engage the pin, and the locking member comprises a rivet to engage the rivet engaging element.

1 3. A pinned coupling according to claim 12 wherein the load bearing pin is of such length that when it is received in the passage, an outer part of the first portion of the passage is not occupied by the pin, and the rivet extends into said outer part behind the pin, the rivet engagement element being inserted in the unoccupied outer part of the first portion of the passage and being engaged by the rivet to hold the pin.

14. A pinned coupling according to claim 13 wherein said element has an opening aligned with the opening in the first member, the rivet extending through the opening in said first member into the opening in the rivet engagement element.

1 5. A pinned coupling according to claim 14 wherein the rivet engaging element has a recess therein which communicates with said opening in the element into which recess the end of the rivet extends, to permit the end of the rivet to be expanded when inserted, to a diameter greater than the diameter of the opening in the rivet engaging element.

1 6. A pinned coupling according to any one of claims 13 to 1 5 wherein the opening in the first member in which the rivet is received is countersunk at the outer end thereof, to permit the rivet head to lie flush or substantially flush with the surface of the first member.

1 7. A pinned coupling acording to any one of claims 14 to 16 where dependent on claim 14 wherein rivet engaging element comprises a cupshaped insert, having a cylindrical wall closed by an end cap, the opening being provided in the peripheral wall.

1 8. A pinned coupling according to claim 1 7 where dependent on claim 1 5 wherein the recess into which the end of the rivet extends may thus comprise the interior of the insert.

19. A pinned coupling according to claim 1 7 or claim 1 8 wherein the cup-shaped insert is received in the outer end of the first portion of the passage with the open end of the insert lying adjacent to the end of the pin.

20. A pinned coupling according to claim 1 7 or claim 18 or claim 19 wherein the insert is made as a pressing in mild steel, or low carbon steel to increase the wear resistance of the insert.

21. A pinned coupling according to any one of claims 14 to 16 where dependent on claim 14 wherein the rivet engagement element comprises a hollow pin-like element, the rivet being received in an end of the pin.

22. A pinned coupling according to any one of claims 14 to 1 6 where dependent on claim 14 wherein the rivet engaging element is solid and has a recess bored therein, which recess communicates with the opening in the element, to permit the end of the rivet to be expanded.

23. A pinned coupling according to claim 22 wherein the open end of the recess lies adjacent the end of the pin.

24. A pinned coupling according to claim 22 or claim 23 wherein the element is a disc-like element having an opening extending transversely therethrough, the rivet extending through the opening.

25. A pinned coupling according to any one of claims 22 to 24 wherein a closure means is provided to close the end of the bore.

26. A pinned coupling according to any one of claims 12 to 25 wherein the rivet is a blind rivet, the end of the rivet expanding within the opening or recess of the rivet engaging element.

27. A pinned coupling according to any one of claims 12 to 25 wherein two rivets in corresponding spaced openings in the first member are provided.

28. A pinned coupling according to any one of the preceding claims wherein the load bearing pin is non-circular and the passage circular, whereby the pin rotates in the passage as a loop in the third part of the passage through which the pin extends, pivots.

29. A pinned coupling according to claim 28 wherein the opening or openings in the element comprise a slot or slots which enable the noncircular pin to rotate in the passage through an angle restricted by the extent of the slots.

30. A pinned coupling according to claim 28 wherein the slot comprises a circumferential groove whereby the pin may rotate without restriction.

31. A pinned coupling according to any one of the preceding claims wherein the locking member or members are preferably made of steel or copper/nickel alloy.

32. A pinned coupling according to any one of the preceding claims wherein the retaining element is stronger than the locking member or members so that if the coupling is exposed to excess load, the or each locking member shears before the element fails.

33. A pinned coupling according to any one of the preceding claims wherein the second portion of the passage in the second member is blind, and only the end of the load bearing pin in the first portion of the passage requires retaining means.

34. A pinned coupling according to any one of claims 1 to 32 wherein the second portion of the passage in the second member may be open and thus extend through the second member.

35. A pinned coupling according to claim 34 wherein further retaining means are provided to retain the pin in the second portion of the passage.

36. A pinned coupling according to any of the preceding claims wherein the retaining element lies closely adjacent the walls of the first portion of the passage, to close the passage.

37. A pinned coupling according to any one of the preceding claims wherein the coupling comprises a clevis end of a load bearing component to which it is desired to attach a member.

38. A method of connecting a loop to a load bearing member comprising a pinned coupling of the type specified, comprising the steps of locating the loop in a space between first and second members of the pinned coupling, inserting a load bearing pin into a passage (as herein defined) which extends through and between said first and second members, to entrap the loop in said space, engaging at least one locking member in an opening in said first member which intersects with said passage to engage a retaining element received therein.

39. A method according to claim 38 wherein the retaining element is separate from the pin, and the method includes the step of inserting a retaining element in said passage behind the pin to retain the pin in the passage prior to engaging the locking member.

40. A method according to claim 38 wherein the retaining element comprises a rivet engaging element and the locking member a rivet engaging element and the locking member a rivet, the method including the step of forming an opening in the rivet engaging element, after the rivet engaging element has been inserted in the outer part of the passage.

41. A pinned coupling of the type specified substantially as hereinbefore described with reference to and as shown in Figures 1 to 3, or 4 to 7 or Figure 8 of the accompanying drawings.

42. A method of connecting a loop to a load bearing member substantially as hereinbefore described with reference to Figures 1 to 3 or 4 to 7 or Figure 8 of the accompanying drawings.

43. Any novel feature or novel combination of features disclosed herein and/or illustrated in the accompanying drawings.