Technical Field of the Invention

The present invention relates to fastening pins for forming part of shackle locks. Particularly, but not exclusively, the present invention relates to fastening pins for forming part of shackle locks for off-shore applications.

Background to the Invention

Shackles are often used in order to secure objects. A shackle comprises a substantially u-shaped loop of material, often metal, into which an object, such as a ring or rope, is inserted. A shackle pin is used to close the loop of the shackle, thus fastening the object inside the loop of the shackle.

In existing shackle pins, a nut is used to secure a threaded shackle pin to the shackle. In other existing shackle pins, a hole is formed perpendicularly through the pin, into which a smaller pin or bar is inserted to secure the shackle pin in the shackle. Some shackle pins include both fastening means detailed above.

Other existing shackle pins comprise screw threads which can be used to engage corresponding screw threads in the cavity of the shackle, in order to secure the pin within the shackle. These shackle pins are often ‘moused’, where a wire or zip-tie is fastened through a hole in the pin and through the shackle itself, in order to ensure the shackle pin does not come loose. However, in heavy duty situations, the screw thread may be stripped, or the wire or zip-tie may be insufficient to prevent the pin coming loose, and thus the pin fails and the shackle is not fastened.

All the shackle pins detailed above require manual fastening by a user, which can result in insufficient fastening, or sometimes even a lack of fastening entirely.

It is an object of the present invention to provide a shackle pin which partially or entirely alleviates the above issues in existing shackle pins.

Summary of the Invention

According to a first aspect of the present invention, there is provided a fastening pin for use as part of a shackle lock, the fastening pin comprising a shaft extending for a length, a projection attached to the shaft at a first location along the length and projecting perpendicularly to the length, and at least one retractable protrusion located on the shaft at a second location along the length, the or each retractable protrusion operable to move between a first position in which the or each retractable protrusion protrudes from the shaft perpendicular to the length and a second position in which the retractable protrusion is retracted into the shaft, wherein in use the shaft is inserted into a shackle to form a shackle lock and a shackle is held on the shaft between the projection and the at least one retractable protrusion.

The fastening pin having a retractable protrusion (or retractable protrusions) means the fastening pin does not require a nut, bar, additional pin, cable tie or any other separate component to hold a shackle on the shaft. The retractable pin is in the second position to allow the fastening pin to be inserted into the shackle, and then moves to the first position to hold the shackle on the fastening pin. As such, the user is not required to fasten the pin in the shackle themselves, and so there is no risk they will fasten the pin too loosely or forget to fasten the pin in place. In cases where the fastening pin is used with a separate component such as a nut, wire, cable tie or second pin to secure it, the or each retractable protrusion acts as a fail-back and/or additional method of securing the fastening pin. Therefore, they reduce the chances of the shackle lock unlocking unintentionally.

Further to the above, the fastening has the advantage that it can fit any and all types of shackles, with or without a nut, cable tie, wire or second pin to additionally lock the shackle lock. As such, a user does not require a specially modified shackle to use the fastening pin, and can use their current shackle. This results in it being easier and cheaper to make use of the fastening pin.

The shaft may extend for the length from a first end to a second end. The projection may be attached near the first end. The or each retractable protrusion may be located near the second end.

The projection may be a head. The projection may be positioned at the first end. The projection may be integrally formed with the shaft. The projection may comprise a grip. The grip may comprise a hexagonal surface area. The grip may be an outermost edge of the projection. The or each retractable protrusion may be fully retracted into the shaft when in the second position.

The fastening pin may comprise a at least one biasing component, operable to bias the or each retractable protrusion towards the first position. With the or each retractable protrusion biased towards the first position, a user does not need to worry about moving the retractable protrusion or protrusions to the first position so as to lock the shackle lock. As such, there is even less chance the shackle lock will not be fastened.

The or each biasing component may be operable to apply a biasing force to the or each retractable protrusion perpendicular to the length of the shaft.

There may be a plurality of retractable protrusions. The or each retractable protrusion may be a tooth comprising a crown extending out of the shaft at least when the tooth is in the first position and a root within the shaft in either position. The or each crown may comprise a slope extending towards the shaft. The or each crown may be tapered, towards the second end of the shaft. The or each slope may extend towards the second end. The or each slope and/or taper may extend to a position adjacent the shaft when the respective tooth is in the first position. The or each slope and/or taper may extend for a respective length from near a back of the respective crown to near a front of the respective crown. The or each slope may extend to the front of the respective crown. A width of the or each slope may run from a side to another side of the respective crown. The or each crown may have a wedge-shaped profile along the length of the shaft. The or each crown may be a fin.

The or each slope and/or the taper of the crown extending towards the second end means the or each retractable protrusion automatically moves to the second when it is inserted into the shackle and moved through the shackle aperture. As such, the fastening pin is easier to insert into the shackle.

The or each tooth may comprise a projection between the crown and the root, the projection projecting parallel to the length of the shaft. The projection may be a flange.

The or each biasing component may be a spring. The or at least one biasing component may be a helical spring. The or at least one biasing component may be a V spring. The or each biasing component may be within the shaft. When there is a plurality of retractable protrusions, the or each biasing component may be held between the retractable protrusions.

The shaft may be a cylinder. The or each retractable protrusion may protrude from a circular surface of the cylinder at least when in the first position. In particular, when there is a plurality of retractable protrusions, each retractable protrusion may protrude from a circumference of the circular surface. Further to this, each retractable protrusion may protrude from opposite positions around the circumference of the circular surface.

The pin may comprise a cap, the cap attached to the second end of the shaft to form the end of the pin. The shaft may be partially hollow at the second end, wherein a cavity is formed between the cap and the shaft. The or each retractable protrusion and/or biasing component may be held within the cavity. The shaft may comprise one of more gaps, wherein the or each retractable protrusion, at least when in the first position, may extend out of the gap or a respective one of the gaps to protrude from the shaft.

The shaft may comprise one or more apertures, wherein the or each retractable protrusion, at least in the first position, protrudes from the aperture or a respective one of the apertures. The or each aperture may be cylindrical. The or each aperture may extend along at least part of a line running perpendicular to and through a central axis running along the length of the shaft. When the shaft is a cylinder, the line may be a diameter of the cylinder. When there is one aperture, the aperture may extend along the entire diameter. When there are two retractable protrusions and one aperture, each retractable protrusion may protrude from a respective end of the aperture. The or each retractable protrusion may be held within the aperture.

The pin may comprise a tube, wherein the or each retractable protrusion and/or biasing component is held within the tube and the tube is fitted within the aperture of the shaft. The tube and aperture of the shaft may form an interference fit. The or each retractable protrusion may extend from a respective end of the tube.

The cap may comprise one or more apertures, the or each retractable protrusion extending through the aperture or a respective one of the apertures. The or each retractable protrusion may be held within the or each aperture in the cap. The aperture may be a channel, extending along a line running perpendicularly to and through a central axis along the length of the shaft. When the shaft is cylindrical, the line may be a diameter of the cylinder.

When there are two retractable protrusions, one retractable protrusion may be received into the other. When there are two teeth, one root may comprise a rod and the other a tube, wherein the rod is receivable into, and movable along, the tube. Alternatively, each root may be a rod. When the or at least one of the biasing components is a helical spring, the helical spring may coil around the roots.

The pin may comprise a fastening component operable to fasten the pin to a shackle. The fastening component may be a screw thread. The fastening component may be on the shaft. The fastening component may be on an outer surface of the shaft. When the shaft is a cylinder, the fastening component may be on a circular surface of the shaft. The fastening component may be located at a third location along the length of the shaft. The third location may be between the first location and the second location. The third location may be adjacent the second location.

According to a second aspect of the present invention there is provided a shackle lock, comprising a shackle and a fastening pin according to the first aspect.

According to a third aspect of the present invention there is provided a method of forming a shackle lock, comprising the steps of providing a shackle and a fastening pin according to the first aspect, moving the or each retractable protrusion to the second position, inserting the shaft into the shackle so the shackle is on the shaft between the projection and the or each retractable protrusion, and then moving the or each retractable protrusion to the first position.

According to a fourth aspect of the present invention there is provided a key for unlocking a fastening pin according to the first aspect, the key comprising a body having an opening in an external surface of the body, the opening sized to fit the shaft of the fastening pin within it, the key being operable to slide onto and along the shaft via the opening and so move the or each retractable protrusion from the first position to the second position. The key means a user does not need to push the or each retractable protrusion to the second position to unlock the fastening pin using their fingers, and the fastening pin does not require a means to retract the retractable protrusions to the second position. The key therefore means the fastening pin is easier to use, without the fastening pin needing to be more complex to make.

The body may be a cuboid. The opening may be a hole. The hole may extend through the body. The opening may be sized such that a circumferential surface of the part of the shaft contacts an internal surface of the body at the or each position around the circumference at which the or each retractable protrusion is located. The opening may be sized such that the circumferential surface contacts the internal surface of the body at all positions around the circumference. The internal surface may be cylindrical.

The opening may be circular. The opening may be positioned at or near one end of the body. The other end of the body may be a handle.

According to a fifth aspect of the present invention there is provided a fastening pin according to the first aspect of the present invention and a key according to the fourth aspect of the present invention.

According to a sixth aspect of the present invention there is provided a shackle lock according to the second aspect of the present invention and a key according to the fourth aspect of the present invention. Detailed Description of the Invention

In order that the invention may be more clearly understood one or more embodiments thereof will now be described, by way of example only, with reference to the accompanying drawings, of which:

Figure 1 is a side view of an embodiment of the fastening pin; Figure 2 is side view of the fastening pin of figure 1 when part of a shackle lock; Figure 3 is a side cross-section of the fastening pin of figure 1 when part of a shackle lock;

Figure 4 is a front perspective view of the second end of the fastening pin of figure 1 when part of a shackle lock, with the cap removed; Figure 5 is a back-perspective view of the second end of the fastening pin of figure 1, with the shaft and shackle made see-through;

Figure 6 is a side cross-section of a second embodiment of a fastening pin;

Figure 7 is a side cross-section of a shaft and head of a third embodiment of a fastening pin;

Figure 8 is a side cross-section of the teeth and spring of the fastening pin of figure 7;

Figure 9 shows the fastening pin of figure 1 when part of a shackle lock and a key; and Figure 10 shows the fastening pin, shackle and key of figure 9 with the key on the shackle to unlock it.

Turning to Figure 1, the fastening pin 1 comprises a shaft 2. Disposed at a first end of the shaft 2 is a head 3. The opposite, second end of the shaft 2 is free.

In this embodiment, the shaft 2 is substantially cylindrical, and is provided with a screw thread 4 extending approximately on quarter of the length of the shaft 2 from a point approximately 20% of the length of the shaft 2 from the free end. The pin 1 is comprised of two components, these being the shaft 2 and a cap 5. The shaft 2 extends approximately 95% the length of the pin 1 from the head 3, and the cap 5 fits to the shaft 2 at the opposite end to the head 3, to form the free end of the pin 1. The shaft 2 is a rod. As shown most clearly in figure 4, the shaft 2 comprises a recessed portion 6 at the free end. The recessed portion 6 is a cylindrical recess in the end of the rod, bound by walls 7, the recessed portion 6 being concentric with the rod. The recessed portion 6 has depth approximately 15% of the length of the shaft 2. The diameter of the recessed portion 6 is approximately 90% of the outer diameter of the shaft 2. There are two gap regions 8 in the wall 7, positioned diametrically opposite to each other. The gap regions 8 extend the depth of the recessed portion 6, and have width approximately equal to 5% of the length of the shaft 2 (and thus are substantially square). As shown most clearly in figure 5, the cap 5 comprises a top 9, which is cylindrical and has a diameter substantially equal to that of the shaft 2. The top 9 has a length of approximately 5% the length of the pin 1.

The cap 5 further comprises two segment walls 10, The segment walls 10 forming part of the same circle (diametrically opposite each other) which is concentric with the top 9 and has a diameter of approximately 90% of the diameter of the pin 1. A channel is formed between the two segment walls 10. The segment walls 10 each have a length approximately the same as the depth of the recessed portion 6 of the shaft 2. The circle of the segment walls 10 has a diameter substantially equal to the diameter of the recessed portion 6.

In use, and as best shown in figure 3, the segment walls 10 slot into the recessed portion 6 and are affixed therein, such that the top 9 and the shaft 2 are adjacent. When connected, the end of the rod and segment walls 10 form a cavity 12. This cavity 12 is substantially cuboidal in shape.

The entrance and exit of the channel formed by the segment walls 10 are positioned opposite each other on the circumference of the tube 10. In use, each of the entrance and exit aligns with a respective gap region 8, to form two, oppositely positioned unbroken passages from the outer surface of the wall to the hollow centre of the tube 10.

Retained within the cavity 12 are a pair of teeth 13,14. Each tooth 13, 14 extends within and out of a respective passage. Each tooth 13,14 comprises a substantially cylindrical root 15,16. One tooth 13 has a root which is a tube 15, and the other tooth 14 has a root which is a rod 16. The roots 15,16 of each tooth 13,14 have different diameters, the tube root 15 having a larger diameter than the rod root 16. Indeed, the diameter of the rod root 16 is substantially the same as the diameter of the hollow centre of the tube root 15, to allow the root rod 16 to be received into the tube root 15 of the other tooth 13. The tube root 15 has a diameter substantially the same as the width of the gap regions 8 in the wall 7. The diameter of the hollow centre of the tube root 15 is approximately two thirds of the tube root 15 diameter. The tube root 15 extends into the tooth 13 a length that is approximately 1.5 times its outer diameter. On each tooth 13,14 there is a flange 17 which extends radially outward near the top end of the respective root 15,16. The flange 17 of each tooth 13,14 has a diameter approximately one third larger than the diameter of the tube root 15, and equal to the width of the entrance and exits of the channel formed by the segment walls 10. In use, each flange 17 is within the channel.

Each tooth 13,14 also comprises a fin 18 which protrudes perpendicularly from the respective root 14, 15. Each fin 18 has a square base which is substantially the same size as the gap regions 8 in the wall 7 of the shaft 2. Each fin 18 each has a uniform trapezoidal profile, having two rectangular walls of differing lengths which protrude perpendicularly from the flange, and an inclined planar surface which connects the two. The shorter wall has a length approximately the same as the thickness of the wall 7 of the shaft 2. The longer wall has a length approximately twice that of the short wall.

In use, the fins 18 extend in and out of the gap regions 8. The fins 18 are oriented such that the longer of their walls is disposed towards the head 3 of the pin 1, and the inclined plane slopes towards the free end of the pin 1.

In this arrangement, a helical spring 19 is disposed and held between the flanges 17 of the two teeth 13,14, thus enclosing the respective substantially cylindrical portions 15,16. The spring 19 biases the flanges 17 of the teeth 13,14 against the inner surface of the wall 7 of the shaft 2 and ensures the fins 18 are protruding from the shaft

2.

In use, the free end of the pin 1 is inserted into a shackle. The inclined plane of each fin 18 contacts the shackle, and as force is applied to move the pin 1, the teeth 13,14 are forced radially inwards, compressing the spring 19. When a sufficient force is applied to the pin 1, the outward radial bias supplied by the spring 19 will no longer be sufficient to ensure the fins 18 protrude from the shaft 2, and the pin 1 shall move through the shackle. If necessary, the pin 1 must be turned in order to engage the screw thread 4 with a corresponding screw thread in the cavity 12. When the pin 1 has been inserted so far that the gap regions 8 are no longer within the cavity 12, the spring 19 force the teeth 13,14 radially outward, and the fins 18 protrude from the shaft 2. As the longer walls of the fins 18 now protrude from the shaft 2, are biased towards the cavity 12 by the spring 19 and lie substantially parallel to the surface in which the cavity 12 is disposed, the pin 1 is securely fastened in the cavity 12.

To remove the pin 1, the user must manually compress the spring 19 by pressing the fins 18 together to force the two teeth 13,14 radially inward, and simultaneously move the pin 1 through the shackle. The pin can then be reused as above.

In the embodiment shown in figures 6, the cap 20 is a round tube insert. Further to this, the teeth 21, 22 have no flanges, and instead the roots 23, 24 are thin rods extending from the bases of the crowns 25, 26. The spring 19 is held between the bases of the crowns 25, 26, with the spring 19 coiled around the roots 23, 24. The gaps 27 through the wall 7 have a tapered side, which is the side closest the free end. The side tapers tapering inwards towards the outer surface of the shaft. The gaps 27 are smaller than the bases of the crowns 25, 26, such that the crowns 25, 26 can extend out of the gaps 27 but cannot exit the cavity 12 through them.

In the cavity 12 there is also a V spring 28. The V spring 28 is contained between the bases of the crows 25, 26, the bottom of the V pointing towards the cap 20. The V spring 28 further biases the teeth 21, 22 out of the gaps 27.

To form the pin 1, the springs 19, 28 are placed in between the teeth 21, 22, and then the teeth 21, 22 and springs 19. 28 are inserted into the cavity 12 via the free end (with the cap 20 removed). The teeth 21, 22 and springs 19, 28 are then pushed down the shaft until the teeth 21, 22 extend out of their respective gaps 27. The cap 20 is then inserted into the free end.

In the embodiment shown in figures 7 and 8, the pin 1 is one component, there being a shaft 28 but no cap. Just beyond the screw thread 4 (i.e. towards the free end). There is an aperture 29 running through the shaft 2. The aperture 29 is cylindrical, running along the diameter of a cross-section of the shaft 2.

The teeth 30, 31 differ from those of the first embodiment in that they have no flanges. The teeth 30, 31 and the spring 19 held between them are within a tube 32. While the diameter of the tube 32 is large enough to accommodate the teeth 30, 31, the ends of the tube 32 are partially closed off to form circular openings 33 (concentric with the tube 32) with smaller diameters. The diameters of the openings 33 are smaller than the bases of the crowns 34, 35 of the teeth 30, 31, such that the teeth 30, 31 and the spring 19 are held within the tube 32.

To form the pin 1, the tube 32 is inserted into the aperture 29. The tube 32 and aperture 29 form an interference fit, thereby holding the tube 32 within the aperture 29. The length of the tube 32 matches the length of the aperture 29, such that the crowns 34, 35 extend out of the cylindrical surface of the shaft 2.

Figures 9 and 10 show a key 40. The key 40 is a cuboid body 41 with a circular hole 42 extending through it near one end of the body 41. The other end of the body 41 forms a handle 43. The free end of the shaft 2 can slide into the hole 42, the circumferential surface of the shaft 2 contacting the side of the hole 42.

In use, a user holds the key 40 by the handle 43 and slides the hole 42 over the fastening pin 1 when it is locked into a shackle. The key 40 will push the teeth 21, 22 into the shaft 2, thereby unlocking the fastening pin 1 from the shackle.

The one or more embodiments are described above by way of example only. Many variations are possible without departing from the scope of protection afforded by the appended claims.