Field

The present invention relates to zip lines, for example to trolleys and/or cables for zip lines.

Background to the invention

Typically, a zip line (also known as a zip-line, zip wire, aerial runway or aerial ropeslide) comprises an inclined cable, secured only at upper and lower ends thereof, and a trolley (also known as a bogey), including a freely-rolling pulley. A user (i.e. a load), suspended from the trolley, may be accelerated by gravity from the upper end to the lower end of the inclined cable. In use, the pulley rolls along an uppermost portion of the inclined cable. A gradient of the inclined cable is typically in a range from 1 in 20 to 1 in 30. Usually, the inclined cable sags and appropriate tensioning of the inclined cable is required to control acceleration of the user. Since the inclined cable is secured only at the upper and the lower ends thereof, the inclined cable is restricted to a linear path, without lateral deviations, such as curves or bends.

Hence, there is a need to improve zip lines, for example trolleys and/or cables for zip lines.

Summary of the Invention

It is one aim of the present invention, amongst others, to provide a trolley for a zip line and a cable for a zip line which at least partially obviates or mitigates at least some of the disadvantages of the prior art, whether identified herein or elsewhere.

A first aspect provides a trolley for a zip line, the trolley comprising: a frame comprising a channel, defining a longitudinal axis, having an open side and adapted to be received on a cable of the zip line; and a first set of projections, including a first projection and a second projection, coupled to the frame and mutually spaced apart along the longitudinal axis, wherein the trolley is retained on the cable by the first set of projections projecting across the open side and wherein the first set of projections provides a bearing surface for supporting the trolley on the cable; wherein the first set of projections is arrangeable in: a first arrangement, wherein the first projection and the second projection cantilever across the open side; and a second arrangement, wherein the first projection or the second projection cantilevers across the open side; wherein the trolley is arranged to move from the first arrangement to the second arrangement by a force applied on the first set of projections.

A second aspect provides a cable for a zip line, providing a running surface for a trolley, having a tether extending transversely away therefrom.

A third aspect provides a zip line comprising a trolley according to the first aspect and a cable according to the second aspect.

A fourth aspect provides a bracket for a cable for a zip line, the bracket comprising: a frame comprising a channel, defining a longitudinal axis, having an open side and adapted to receive the cable therein; and a first set of projections, including a first projection and a second projection, coupled to the frame and mutually spaced apart along the longitudinal axis, wherein the cable is retained in the channel by the first set of projections projecting across the open side and wherein the first set of projections provides a bearing surface for supporting the cable thereupon; wherein the first set of projections is arrangeable in: a first arrangement, wherein the first projection and the second projection cantilever across the open side; and a second arrangement, wherein the first projection or the second projection cantilevers across the open side; wherein the bracket is arranged to move from the first arrangement to the second arrangement by a force applied on the first set of projections.

A fifth aspect provides an assembly comprising a bracket according to the fourth aspect, a cable and optionally, a trolley.

Detailed Description of the Invention

According to the present invention there is provided a trolley, as set forth in the appended claims. Also provided is bracket. Other features of the invention will be apparent from the dependent claims, and the description that follows.

Trolley

The first aspect provides a trolley for a zip line, the trolley comprising: a frame comprising a channel, defining a longitudinal axis, having an open side and adapted to be received on a cable of the zip line; and a first set of projections, including a first projection and a second projection, coupled to the frame and mutually spaced apart along the longitudinal axis, wherein the trolley is retained on the cable by the first set of projections projecting across the open side and wherein the first set of projections provides a bearing surface for supporting the trolley on the cable; wherein the first set of projections is arrangeable in: a first arrangement, wherein the first projection and the second projection cantilever across the open side; and a second arrangement, wherein the first projection or the second projection cantilevers across the open side; wherein the trolley is arranged to move from the first arrangement to the second arrangement by a force applied on the first set of projections.

In this way, in use in the first arrangement, the trolley is suspended from the cable, extending through the channel, by the first set of projections, which provide the bearing surface for supporting the trolley on the cable. In the first arrangement, the first projection and the second projection cantilever across the open side of the channel and hence in the first arrangement, the bearing surface is provided by the first projection and the second projection. In other words, in the first arrangement, the trolley is suspended from the cable by the first projection and by the second projection. Upon encountering or contacting an obstacle, such as an intermediary securing such as a tether or a guy for the cable, the trolley moves from the first arrangement to the second arrangement due to the force applied on the first set of projections by the obstacle, for example. That is, the obstacle urges the trolley to move from the first arrangement to the second arrangement, In contrast to the first arrangement, in the second arrangement, the first projection or the second projection cantilevers across the open side of the channel and hence in the second arrangement, the bearing surface is provided by the first projection or by the second projection. In other words, in the second arrangement, the trolley is suspended from the cable by the first projection or by the second projection. For example, in the second arrangement, the trolley may be suspended from the cable transiently by the second projection and subsequently, the trolley may be suspended from the cable transiently by the first projection or by a third projection, for example. Thereafter, the trolley may move back to the first arrangement. In more detail, the force may be applied on the first projection by the obstacle (i.e. the first projection contacts the obstacle), thereby moving the first projection such that the first projection no longer provides a part of the bearing surface for supporting the trolley, which is thus supported on the bearing surface provided by the second projection (i.e. the second arrangement). Subsequently, the force may be applied on the second projection by the obstacle (i.e. the second projection contacts the obstacle), thereby moving the second projection such that the second projection no longer provides a part of the bearing surface for supporting the trolley, which is thus supported on the bearing surface provided by the first projection (i.e. the second arrangement) or by a third projection (e.g. a third arrangement), for example. That is, generally the trolley is supported on the cable in the first arrangement, by the first projection and by the second projection. Upon encountering or contacting an obstacle, the first projection and the second projection are successively moved so as to avoid the obstacle while the trolley remains supported on the cable in the second arrangement, by the first projection or by the second projection. Having traversed the obstacle, the trolley moves back to the first arrangement.

Conventional zip lines are free of obstacles since the trolley pulley rolls along an uppermost portion of the inclined cable, from which the user is suspended. Particularly, an obstacle on the cable conventionally prevents rolling of the trolley pulley therepast. Hence, conventionally, the cable is secured only at the upper and the lower ends thereof, without any intermediary securing which would otherwise present an obstacle.

Since the trolley according to the first aspect is capable of traversing obstacles, such as intermediary securing for the cable, the cable may be thus additionally secured between the upper and the lower ends thereof, so as to counter sag therein, thereby reducing tension required in the cable while improving control of acceleration of a user. Since the tension in the cable may be reduced, a relatively lighter gauge of cable may be employed, thereby also diminishing the sag. Additionally and/or alternatively, since the inclined cable may now be secured at intermediate positions between the upper and the lower ends thereof, the inclined cable is not restricted to a linear path and thus a non-linear path, for example having lateral deviations such as curves or bends and/or having one or more descending portions, ascending portions and/or horizontal portions, may be provided.

Trolley for a zip line

The first aspect provides the trolley for the zip line. It should be understood that the trolley is suitable for a conventional cable of a zip line, for example a conventional cable secured only at the upper and lower ends thereof. It should be understood that the trolley is suitable for a cable for a zip line secured at the upper and lower ends thereof and at intermediate positions therebetween. As described previously, such intermediate securing is conventionally not possible.

It should be understood that the trolley is suitable also for applications, such as guide or safety rails or cables for safe working at height or hazardous situations, such as at sea or offshore. For example, horizontal safety rails or cables may be secured at intermediate positions therealong, conventionally requiring a user to unclip and re-clip so as to traverse the obstacles presented by the intermediate securing. In contrast, the trolley according to the first aspect enables the user to traverse such obstacles without unclipping, thereby improving safety. Frame

The trolley comprises the frame.

In one example, the frame comprises an open structure (also known as a framework or cage), for example provided by one or more struts and/or one or more ties. In one example, the frame comprises a closed structure and/or a monocoque structure.

Channel

The frame comprises the channel, defining the longitudinal axis, having the open side and adapted to be received on the cable of the zip line.

That is, the cable extends, in use, through the channel (i.e. through a passageway provided thereby), along the longitudinal axis defined thereby, for example by a length thereof. It should be understood that the channel has two opposed open ends for the cable to pass therethrough. It should be understood that the channel, for example having or forming a U- shaped cross-section, has a plurality of closed sides, thereby retaining the channel on the cable transversely to the longitudinal axis, for example laterally (e.g. left and right) and vertically upwards, so that the trolley may not be removed from (i.e. come off) the cable, in use. For example, the channel prevents or attenuates yawing of the trolley about the cable. For example, the channel, together with the first set of projections, prevents or attenuates pitching of the trolley about the cable. In contrast, since the opposed ends of the channel are open, the channel does not prevent or attenuate rolling of the trolley about the cable. It should be understood that the channel has the open side, opposed to a closed side. In the absence of the first set of projections, the channel may be received on the cable via the open side. It should be understood that the cable may be received via an open side or an open end, for example having no occlusions preventing the cable from being received therethrough. In contrast, it should be understood that the cable may not be received via a closed side, for example having one or more occlusions preventing the cable from being received therethrough.

In one example, the channel, defining the longitudinal axis, has the open side (for example, an open upper side), a mutually opposed closed side (for example, a closed lower side), two mutually opposed closed sides therebetween (for example, closed left and right sides) and mutually opposed open ends. In one example, the channel comprises and/or is a continuous channel, for example having a constant cross-section such as a U-shaped channel. In this way, a complexity of the channel is reduced. In one example, the channel comprises and/or is a discontinuous channel, for example having a non-constant cross-section such as a formed to provide one or more occlusions preventing the cable from being received via closed sides thereof. In this way, a mass of the channel may be reduced.

In one example, the trolley has a plane of symmetry defined, at least in part, by the longitudinal axis. In this way, weight distribution of the trolley and hence balance, for example across the channel, is improved.

Cable

Cables for zip lines are known. In one example, the cable is according to the second aspect.

Projections

The trolley comprises the first set of projections, including the first projection and the second projection. It should be understood that the first projection is comprises and/or is a protrusion or male member, such as a finger i.e. an elongate member.

The first set of projections, including the first projection and the second projection, are mutually spaced apart along the longitudinal axis, for example by a predetermined spacing. In this way, since the trolley moves along the cable along the longitudinal axis for example in a direction aligned therewith at a finite speed, the first projection and the second projection encounter an obstacle at different times, such that the first projection and the second projection may be moved separately so as to avoid the obstacle whilst retaining the trolley on the cable. In one example, the predetermined spacing is determined based on a size of the obstacle such that the predetermined spacing is at least the size of the obstacle.

The trolley is retained on the cable by the first set of projections projecting across the open side. That is, the first set of projections prevents the trolley from being removed from the cable via the open side. In other words, the trolley is captive on the cable. It should be understood that if the trolley comprises two or more sets of projections, the trolley is thus retained on the cable in part by the first set of projections.

The first set of projections provides the bearing surface for supporting the trolley on the cable. That is, the trolley runs and/or rolls on the cable on the bearing surface provided by the first set of projections. It should be understood that the first projection and the second projection each provide at least a part of the bearing surface. It should be understood that the first set of projections structurally supports a load (i.e. a weight and/or lateral forces) due to the trolley and a user, for example, suspended therefrom, which is transferred to the first set of projections.

In one example, the first projection comprises and/or is a non-rolling projection and the bearing surface comprises and/or is a plain bearing surface. In this way, the first projection slides on the cable. Such non-rolling projections are relatively simple. In one example, the first projection comprises a rolling projection, for example having one or more roller bearings, and the bearing surface comprises a roller bearing surface. In this way, the first projection rolls on the cable, thereby reducing frictional resistance. Suitable roller bearings include ball bearings such as deep-groove ball bearings. In one example, the roller bearings are sealed (i.e. having a seal, also known as a shield or a closure), thereby reducing a maintenance requirement and/or improving safety. Type ZZ, 2RS and/or 2RU seals are preferred. In one example, the first projection comprises a passive rolling projection (i.e. not driven). In one example, the first projection comprises an active rolling projection (i.e. driven, for example by an electric motor included on the trolley together with optionally a power supply and/or a power controller).

In one example, the first projection comprises a projection having a non-constant cross-section or a constant cross-section, for example a cuboidal, an hexagonal or a cylindrical projection, for example suitable for non-rolling projections. Cylindrical projections are also suitable for rolling projections. In one example, the first projection comprises a tapering projection, for example a pyramidal or a frustoconical projection, for example suitable for non-rolling projections. Frustoconical projections are also suitable for rolling projections. Tapering projections improve lift off from the cable and/or touch down onto the cable, during moving from the first arrangement to the second arrangement and/or vice versa. Particularly, lift off from the cable and/or touch down onto the cable are improved since support of the trolley by the tapering first projection is gradually removed and/or gradually replaced. Additionally and/or alternatively, lift off from the cable and/or touch down onto the cable are improved since the trolley may pitch during moving from the first arrangement to the second arrangement and/or vice versa, thereby displacing the trolley relative to the cable, which may be accommodated by the tapering first projection.

The first set of projections is coupled to the frame. It should be understood that the projections are moveably coupled to the frame, for example slidably and/or rotationally.

In one example, the first set of projections is slidably, for example freely slidably, coupled to the frame. In this way, the first projection and the second projection may be moved slidably laterally, so as to traverse the obstacle. For example, the first arrangement may correspond with a closed configuration and the second arrangement may correspond with a partially open configuration, in which the first projection or the second projection is moved slidably laterally. In one example, the first projection and the second projection are independently (i.e. individually) slidably coupled to the frame. In this way, the first projection and the second projection may be moved slidably laterally individually i.e. in turn, not simultaneously.

In one example, the first set of projections is rotatably coupled, for example freely rotatably optionally unidirectionally, to the frame, having a rotational axis orthogonal or oblique to the longitudinal axis. In this way, the first projection and the second projection may be moved rotationally, so as to traverse the obstacle. If the rotational axis is oblique to the longitudinal axis, lift off and/or touchdown may be improved, as described previously. If the first set of projections is unidirectionally rotatably coupled to the frame, the trolley is limited to travelling unidirectionally along the cable. In this way, a direction of travel may be defined. In one example, the trolley comprises a first hub, rotatably coupled to the frame, wherein the first set of projections extends therefrom, for example radially, for example as spokes. In this way, encountering or contacting an obstacle, such as intermediary securing such as a tether or a guy for the cable, the first projection of the set thereof is rotated away thereby and thus replaced by the second projection, which may be in turn similarly replaced by a third, for example. In this way, at least one projection cantilevers across the open side at all times, thereby supporting the trolley on the cable. In one example, the trolley comprises a set of hubs, as described below, including a first hub, rotatably coupled, for example freely rotatably coupled optionally unidirectionally, to the frame, wherein the first set of projections extends therefrom, for example radially. In one example, the first hub has a rotational axis orthogonal or oblique to the longitudinal axis. In one example, the rotational axis is at an angle 0° < a < 30° with respect to a vertical datum V. In one example, the first set of projections is inclined at an angle 45° < ? < 90° with respect to a vertical datum V. In this way, lift off from the cable and/or touch down onto the cable are improved since support of the trolley by the set of projections is gradually removed and/or gradually replaced.

In one example, the first projection and the second projection are dependently moveable. In this way, movement of the first projection causes and/or is due to movement of the second projection. For example, upon encountering or contacting an obstacle, the force may be applied on the first projection, thereby causing movement of the second projection or vice versa. In this way, at least one of the first projection and the second projection supports the trolley in the first arrangement and the second arrangement.

In one example, wherein the first projection and the second projection are independently moveable. In this way, movement of the first projection is independent (i.e. separate) from movement of the second projection. For example, upon encountering or contacting an obstacle, the force may be applied on the first projection, thereby causing movement of the first projection without movement of the second projection. In this way, the first projection and the second projection may individually support the trolley.

In one example, the first set of projections includes N projections, including the first projection and the second projection, wherein N is a natural number greater than or equal to 3, for example 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12, preferably at least 5 for example 6 or 8. By increasing the number of projections, the trolley may be supported by an increased number thereof. The N projections of the first set of projections may be as described with respect to the first projection and/or the second projection. In one example, the N projections are mutually equispaced, for example along the longitudinal axis and/or circumferentially.

Second set of projections

In one example, the trolley comprises a second set of projections, including a first projection and a second projection. The second set of projections maybe has described with respect to the first set of projections.

In one example, the first set of projections and the second set of projections are mutually spaced apart along the longitudinal axis or wherein the first set of projections and the second set of projections are mutually opposed. In this way, pitching of the trolley while traversing the obstacle may be relatively reduced since the trolley may be supported by projections spaced relatively further apart. In one example, the first set of projections and the second set of projections mesh, for example across the open side.

In one example, the trolley comprises M sets of projections, wherein M is a natural number greater than or equal to 1 , for example 1 , 2, 3, 4, 5 or 6, preferably an even number for example 2 or 4. An even number of sets of projections may contribute towards improving weight distribution across the channel, for example. By increasing the number of sets of projections, the trolley may be supported by an increased number thereof. The M sets of projections may be as described with respect to the first set of projections.

Hubs

In one example, the trolley comprises a set of hubs including a first hub, rotatably coupled, for example freely rotatably coupled, to the frame, wherein the first set of projections extends therefrom, for example radially, as described previously. In one example, the set of hubs includes H hubs, wherein H is a natural number greater than or equal to 1 , for example 1 , 2, 3, 4, 5 or 6. In one example, the trolley comprises M sets of projections and the set of hubs comprises H hubs, wherein H is equal to M. In one example, the first hub has a rotational axis orthogonal or oblique to the longitudinal axis. If the rotational axis is oblique to the longitudinal axis, lift off and/or touchdown may be improved, as described previously. This is advantageous if hubs are arranged on mutually opposed sides of the channel. In one example, the set of hubs includes an even number of hubs, wherein the hubs are mutually opposed or staggered. In one example, the set of hubs includes an odd number of hubs, wherein the hubs are mutually staggered. In one example, the first set of projections and the second set of projections, extending respectively from the first hub and a second hub, mesh, for example across the open side. In this way, support of the trolley may be improved since the respective projections may be more closely spaced along the longitudinal axis. In one example, the first set of projections and the second set of projections, extending respectively from the first hub and a second hub, do not mesh. In this way, collision between respective projections may be avoided, for example.

First arrangement

The first set of projections is arrangeable in the first arrangement, wherein the first projection and the second projection cantilever across the open side. The first arrangement corresponds with a normal, running arrangement, in which the trolley is freely running on the cable. In this way, in use in the first arrangement, the trolley is suspended from the cable, extending through the channel, by the first set of projections, which provide the bearing surface for supporting the trolley on the cable. It should be understood that the first projection and the second projection cantilever sufficiently far across the open side so as to support the trolley, for example at least as far across as the crown of the cable. In one example, the first projection and/or the second projection extend fully across the open side, for example beyond the open side.

More generally, in one example, the first set of projections is arrangeable in the first arrangement, wherein a plurality of projections of the first set thereof cantilever across the open side.

In one example, the first set of projections is biased, for example resiliently biased, in the first arrangement. In this way, safety is improved since the trolley is supported on the cable by the first projection and the second projection. In one example, the trolley comprises a biasing member, such as an actuator actuatable by the load suspended from the trolley, configured to bias the first set of projections in the first arrangement. In one example, the trolley comprises a resilient biasing member, for example a mechanical or an elastomeric spring, configured to bias the first set of projections in the first arrangement. For example, the first projection and the second projection may be slidably coupled to the frame and biased in the first arrangement by respective mechanical springs. Upon encountering the obstacle, the first projection is individually moved slidably laterally due to the force applied thereupon, away from the first arrangement to the second arrangement, before moving back to the first arrangement due to the mechanical spring. Subsequently, the second projection is individually moved slidably laterally due to the force applied thereupon, away from the first arrangement to the second arrangement, before moving back to the first arrangement due to the mechanical spring.

In one example, the trolley comprises a support configured to support a distal end of the first projection. It should be understood that the proximal end of the first projection is attached, directly or indirectly, to the frame and thus supported. In this way, the distal end of the first projection is supported, thereby increasing the load that may be suspended from the trolley.

Second arrangement

The first set of projections is arrangeable in the second arrangement, wherein the first projection or the second projection cantilevers across the open side. The second arrangement corresponds with an obstacle traversing arrangement, in which the trolley traverses an obstacle such as intermediary securing for the cable. In contrast to the first arrangement, in the second arrangement, the first projection or the second projection cantilevers across the open side of the channel and hence in the second arrangement, the bearing surface is provided by the first projection or by the second projection i.e. by not both the first projection and the second projection but rather one or the other. Typically, the second arrangement is a temporary arrangement, for traversing the obstacle, though the trolley may freely run on the cable, generally as described with respect to the first arrangement.

More generally, in one example, the first set of projections is arrangeable in the second arrangement, wherein a single projection of the first set thereof cantilevers across the open side.

Moving from the first arrangement to the second arrangement

The trolley is arranged to move from the first arrangement to the second arrangement by the force applied, directly and/or indirectly, on the first set of projections. In this way, the trolley may traverse an obstacle, as described herein.

In one example, the force is applied directly on the first set of projections, for example by the first projection contacting an obstacle. In one example, the force is applied indirectly on the first set of projections, for example by an actuator contacting an obstacle and upon actuation thereof, causing the trolley to move from the first arrangement to the second arrangement. In one example, the actuator comprises and/or is an electrical actuator for example a sensor, such as an optical sensor, or a mechanical actuator for example a linkage or trigger.

In one example, the trolley is arranged to move from the first arrangement to the second arrangement by the force applied on the first projection of the first set of projections, wherein the second projection cantilevers across the open side.

In one example, the trolley is arranged to move within the second arrangement by the force applied on the second projection of the first set of projections, wherein the first projection cantilevers across the open side.

In one example, the trolley is arranged to move from the second arrangement to the first arrangement or an arrangement equivalent thereto, such as wherein a third projection and a fourth projection of the first set of projections cantilever across the open side. In one example, the trolley is arranged to move repeatedly from the first arrangement to the second arrangement and vice versa.

Third arrangement

In one example, the first set of projections is arrangeable in: the second arrangement, wherein the first projection cantilevers across the open side; and a third arrangement, wherein the second projection cantilevers across the open side.

Fourth arrangement

In one example, the first set of projections includes a third projection and a fourth projection, mutually spaced apart along the longitudinal axis, wherein the first set of projections is arrangeable in: a fourth arrangement, wherein the third projection and the fourth projection cantilever across the open side.

Guides

In one example, the trolley comprises a set of guides disposed proximal and/or at an entrance and/or exit of the channel. In this way, the trolley may be guided by the set of guides on the cable.

Attachment member In one example, the trolley comprises an attachment member for attachment of a load thereto. In one example, the attachment member comprises/or is a releasable attachment member. In one example, release of the attachment member requires a use of a tool. In this way, inadvertent or deliberate release of the attachment member, in use, may be avoided, thereby improving safety. In one example, the attachment member comprises a fastener, for example a pin fastener, a split pin (also known as a cotter pin, cotter key or a split cotter), a locking ring, a mouse, or a clamp to restrict release of the attachment member from the frame. In this way, inadvertent or deliberate release of the attachment member, in use, may be avoided, thereby improving safety. In one example, the attachment member comprises a shackle (also known as a gyve), being generally a U-shaped piece of metal secured with a clevis pin or bolt across the opening thereof, or a hinged metal loop secured with a quick-release locking pin mechanism. In one example, the shackle is a bow shackle, a D-shackle, a headboard shackle, a pin shackle, a snap shackle, a threaded shackle or a twist shackle. A pin shackle, closed with an anchor bolt and a split pin and including a securing nut in addition to the split pin, is preferred, since inadvertent or deliberate release of the attachment member, in use, may be avoided. A moused threaded shackle is also suitable. Quick release shackles, for example snap shackles or carabiners, may be readily released, in use, even with one hand and are generally not preferred. Generally, quick release attachment members are not preferred. In one example, the attachment member does not comprise and/or is not a quick release attachment member, for example a quick release shackle.

Preferred example

In one preferred example, the trolley comprises: the frame comprising the channel, defining the longitudinal axis, having the open side and adapted to be received on a cable of the zip line; and the first set of projections includes N projections, including the first projection and the second projection, coupled to the frame and mutually spaced apart along the longitudinal axis, wherein N is a natural number greater than or equal to 3, for example 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12, preferably at least 5 for example 6 or 8, wherein the trolley is retained on the cable by the first set of projections projecting across the open side and wherein the first set of projections provides the bearing surface for supporting the trolley on the cable; wherein the trolley comprises M sets of projections, wherein M is a natural number greater than or equal to 2, for example 2, 3, 4, 5 or 6, preferably an even number for example 2 or 4; wherein the trolley comprises a set of H hubs including a first hub, rotatably coupled, for example freely rotatably coupled, to the frame, wherein the first set of projections extends therefrom, for example radially, wherein H is equal to M, optionally wherein the hubs are mutually opposed or staggered; wherein the first set of projections is arrangeable in: the first arrangement, wherein the first projection and the second projection cantilever across the open side; and the second arrangement, wherein the first projection or the second projection cantilevers across the open side; wherein the trolley is arranged to move from the first arrangement to the second arrangement by the force applied on the first set of projections.

Cable

A second aspect provides a cable for a zip line, providing a running surface for a trolley, having a tether, for example an intermediary securing such as a guy for the cable, extending transversely away therefrom. In this way, the cable may be thus additionally secured between the upper and the lower ends thereof, so as to counter sag therein, thereby reducing tension required in the cable while improving control of acceleration of a user. Since the tension in the cable may be reduced, a relatively lighter gauge of cable may be employed, thereby also diminishing the sag. Additionally and/or alternatively, since the cable may now be secured at intermediate positions between the upper and the lower ends thereof, the cable is not restricted to a linear path and thus a non-linear path, for example having lateral deviations such as curves or bends and/or having one or more descending portions, ascending portions and/or horizontal portions, may be provided.

In one example, the tether comprises and/or is a rigid tether, for example provided by a rod, inserted transversely through a diameter of the cable, having a head to prevent extraction therefrom. In one example, the tether comprises and/or is a cable (i.e. a secondary cable c.f. ahe cable being a primary cable), mechanically coupled to the cable for example by splicing or inserted as described with respect to the rigid tether and/or adhesively coupled to the cable.

In one example, a diameter of the tether is at most a diameter of the cable. In one example, a width of the cable at the tether is at most 150%, preferably at most 125%, more preferably at most 110% of the diameter of the cable. In this way, the width is not significantly increased by the tether. In one example, the running surface provided by the cable for the trolley (i.e. an uppermost portion thereof) is deviated by at most 150%, preferably at most 125%, more preferably at most 110% proximal the tether, compared with an untethered cable. In this way, the running surface is not significantly perturbed by the tether.

Zip line

A third aspect provides a zip line comprising a trolley according to the first aspect and a cable according to the second aspect. Bracket

The fourth aspect provides a bracket for a cable for a zip line, the bracket comprising: a frame comprising a channel, defining a longitudinal axis, having an open side and adapted to receive the cable therein; and a first set of projections, including a first projection and a second projection, coupled to the frame and mutually spaced apart along the longitudinal axis, wherein the cable is retained in the channel by the first set of projections projecting across the open side and wherein the first set of projections provides a bearing surface for supporting the cable thereupon; wherein the first set of projections is arrangeable in: a first arrangement, wherein the first projection and the second projection cantilever across the open side; and a second arrangement, wherein the first projection or the second projection cantilevers across the open side; wherein the bracket is arranged to move from the first arrangement to the second arrangement by a force applied on the first set of projections.

As an alternative to the trolley described with respect to the first aspect, the bracket according to the fourth aspect supports the cable (i.e. a conventional cable) and permits a conventional trolley to traverse therepast, as described with respect to the first aspect, mutatis mutandis. Generally, the bracket is similar to an inverted, static trolley.

In this way, in use in the first arrangement, the cable, extending through the channel, is suspended from the bracket by the first set of projections, which provide the bearing surface for supporting the cable thereupon. In the first arrangement, the first projection and the second projection cantilever across the open side of the channel and hence in the first arrangement, the bearing surface is provided by the first projection and the second projection. In other words, in the first arrangement, the cable is suspended from the bracket by the first projection and by the second projection. Upon contact by a trolley, the bracket moves from the first arrangement to the second arrangement due to the force applied on the first set of projections by the trolley, for example by a pulley thereof. In contrast to the first arrangement, in the second arrangement, the first projection or the second projection cantilevers across the open side of the channel and hence in the second arrangement, the bearing surface is provided by the first projection or by the second projection. In other words, in the second arrangement, the cable is suspended from the bracket by the first projection or by the second projection. For example, in the second arrangement, the cable may be suspended from the bracket transiently by the second projection and subsequently, the cable may be suspended from the racket transiently by the first projection or by a third projection, for example. Thereafter, the bracket may move back to the first arrangement. In more detail, the force may be applied on the first projection by the trolley, for example by a pulley thereof, thereby moving the first projection such that the first projection no longer provides a part of the bearing surface for supporting the cable, which is thus supported on the bearing surface provided by the second projection (i.e. the second arrangement). Subsequently, the force may be applied on the second projection by the trolley as it moves therepast, thereby moving the second projection such that the second projection no longer provides a part of the bearing surface for supporting the cable, which is thus supported on the bearing surface provided by the first projection (i.e. the second arrangement) or by a third projection (e.g. a third arrangement), for example. That is, generally the cable is supported by the bracket in the first arrangement, by the first projection and by the second projection. Upon contact by the trolley, the first projection and the second projection are successively moved so as to avoid the obstacle while the cable remains supported by the bracket in the second arrangement, by the first projection or by the second projection. Having been traversed by the trolley, the bracket moves back to the first arrangement.

It should be understood that the bracket according to the fourth aspect may generally be as described with respect to the trolley according to the first aspect, mutatis mutandis. Hence, description thereof is not repeated, for brevity.

In one example, the first set of projections is biased, for example resiliently biased, in the first arrangement.

In one example, the first set of projections is slidably coupled to the bracket and/or wherein the first set of projections is rotatably coupled to the bracket, having a rotational axis orthogonal or oblique to the longitudinal axis.

In one example, the first projection and the second projection are dependently moveable or wherein the first projection and the second projection are independently moveable.

In one example, the first set of projections includes N projections, including the first projection and the second projection, wherein N is a natural number greater than or equal to 3.

In one example, the first projection comprises a rolling projection wherein the bearing surface comprises a roller bearing surface.

In one example, the bracket comprises a support configured to support a distal end of the first projection. In one example, the bracket comprises a second set of projections, including a first projection and a second projection.

In one example, the first set of projections and the second set of projections are mutually spaced apart along the longitudinal axis or wherein the first set of projections and the second set of projections are mutually opposed.

In one example, the bracket comprises a set of guides disposed proximal and/or at an entrance and/or exit of the channel.

Assembly

The fifth aspect provides an assembly comprising a bracket according to the fourth aspect, a cable and optionally, a trolley.

Definitions

Throughout this specification, the term “comprising” or “comprises” means including the component(s) specified but not to the exclusion of the presence of other components. The term “consisting essentially of’ or “consists essentially of’ means including the components specified but excluding other components except for materials present as impurities, unavoidable materials present as a result of processes used to provide the components, and components added for a purpose other than achieving the technical effect of the invention, such as colourants, and the like.

The term “consisting of’ or “consists of’ means including the components specified but excluding other components.

Whenever appropriate, depending upon the context, the use of the term “comprises” or “comprising” may also be taken to include the meaning “consists essentially of’ or “consisting essentially of’, and also may also be taken to include the meaning “consists of’ or “consisting of’.

The optional features set out herein may be used either individually or in combination with each other where appropriate and particularly in the combinations as set out in the accompanying claims. The optional features for each aspect or exemplary embodiment of the invention, as set out herein are also applicable to all other aspects or exemplary embodiments of the invention, where appropriate. In other words, the skilled person reading this specification should consider the optional features for each aspect or exemplary embodiment of the invention as interchangeable and combinable between different aspects and exemplary embodiments.

Brief description of the drawings

For a better understanding of the invention, and to show how exemplary embodiments of the same may be brought into effect, reference will be made, by way of example only, to the accompanying diagrammatic Figures, in which:

Figures 1A to 1C schematically depict a trolley according to an exemplary embodiment;

Figures 2A to 2B schematically depict a trolley according to an exemplary embodiment;

Figures 3A to 3F schematically depict a trolley according to an exemplary embodiment;

Figures 4A to 4B schematically depict a trolley according to an exemplary embodiment;

Figure 5 schematically depicts a trolley according to an exemplary embodiment;

Figures 6A to 6B schematically depict a bracket according to an exemplary embodiment; and

Figure 7 schematically depicts a trolley according to an exemplary embodiment.

Detailed Description of the Drawings

Generally, like reference signs denote like features.

Figures 1A to 1C schematically depict a trolley 10 according to an exemplary embodiment. Figure 1 A is an upper, front perspective view of a CAD model of the trolley 10, Figure 1 B is an upper, side perspective view and Figure 1C is a rear perspective view. Figures 1A to 1C also depict a cable 1100 according to an exemplary embodiment providing a running surface for the trolley 10, having a tether 1101 , for example an intermediary securing such as a guy for the cable, extending transversely away therefrom.

The trolley 10 is for a zip line, the trolley 10 comprising: a frame 101 comprising a channel 110, defining a longitudinal axis Z, having an open side 111 and adapted to be received on a cable 1100 of the zip line; and a first set of projections 121 , including a first projection 121A and a second projection 121 B, coupled to the frame 101 and mutually spaced apart along the longitudinal axis Z, wherein the trolley 10 is retained on the cable 1100 by the first set of projections 121 projecting across the open side 111 and wherein the first set of projections 121 provides a bearing surface B for supporting the trolley 10 on the cable 1100; wherein the first set of projections 121 is arrangeable in: a first arrangement, wherein the first projection 121A and the second projection 121 B cantilever across the open side 111 ; and a second arrangement, wherein the first projection 121 A or the second projection 121 B cantilevers across the open side 111 ; wherein the trolley 10 is arranged to move from the first arrangement to the second arrangement by a force F applied on the first set of projections 121 .

In this example, the channel 110, defining the longitudinal axis Z, has the open side 111 (for example, an open upper side), a mutually opposed closed side 112 (for example, a closed lower side), two mutually opposed closed sides 113A, 113B therebetween (for example, closed left and right sides) and mutually opposed open ends 114A, 114B.

In this example, the channel 110 is a continuous channel 110, having a constant cross-section such as a U-shaped channel 110.

The first set of projections 121 , including the first projection 121A and the second projection 121 B, are mutually spaced apart along the longitudinal axis Z, for example by a predetermined spacing. In this example, the predetermined spacing is determined based on a size of the obstacle such that the predetermined spacing is at least the size of the obstacle.

In this example, the first projection 121A comprises a rolling projection, for example having one or more roller bearings, and the bearing surface B comprises a roller bearing surface B. In this example, the first projection 121 A comprises a passive rolling projection.

In this example, the first projection 121A comprises a tapering projection, for example a frustoconical projection.

In this example, the first set of projections 121 is freely rotatably coupled to the frame 101 , having a rotational axis orthogonal to the longitudinal axis Z. In this example, the trolley 10 comprises a first hub 131 , freely rotatably coupled to the frame 101 , wherein the first set of projections 121 extends therefrom radially. In this example, the first hub 131 has a rotational axis orthogonal to the longitudinal axis Z.

In this example, the first projection 121 A and the second projection 121 B are dependently moveable. In this example, the first set of projections 121 includes N projections 121 A to 121 F, including the first projection 121 A and the second projection 121 B, wherein N is 6. The N projections of the first set of projections 121 are as described with respect to the first projection 121 A and/or the second projection 121 B. In this example, the N projections 121A to 121 F are mutually equispaced circumferentially.

In this example, the first set of projections 121 is arrangeable in the first arrangement, wherein a plurality of projections of the first set 121 thereof cantilever across the open side 111.

In this example, the trolley 10 comprises a support 140, particularly a slot in the frame 101 , configured to support a distal end of the first projection 121 A.

In this example, the first set of projections 121 is arrangeable in the second arrangement, wherein a single projection of the first set 121 thereof cantilevers across the open side 111.

In this example, the force F is applied directly on the first set of projections 121 , for example by the first projection 121A contacting an obstacle O, particularly the tether 1101 of the cable 1100.

In this example, the trolley 10 is arranged to move from the first arrangement to the second arrangement by the force F applied on the first projection 121 A of the first set of projections 121 , wherein the second projection 121 B cantilevers across the open side 111.

In this example, the trolley 10 is arranged to move within the second arrangement by the force F applied on the second projection 121 B of the first set of projections 121 , wherein the first projection 121 A cantilevers across the open side 111.

In this example, the trolley 10 is arranged to move from the second arrangement to the first arrangement or an arrangement equivalent thereto, such as wherein a third projection 121C and a fourth projection 121 D of the first set of projections 121 cantilever across the open side 111. In this example, the trolley 10 is arranged to move repeatedly from the first arrangement to the second arrangement and vice versa.

In this example, the first set of projections 121 is arrangeable in: the second arrangement, wherein the first projection 121 A cantilevers across the open side 111 ; and a third arrangement, wherein the second projection 121 B cantilevers across the open side 111. In this example, the first set of projections 121 includes a third projection 121C and a fourth projection 121 D, coupled to the frame and mutually spaced apart along the longitudinal axis Z, wherein the first set of projections 121 is arrangeable in: a fourth arrangement, wherein the third projection and the fourth projection cantilever across the open side 111.

Figures 2A to 2B schematically depict a trolley 20 according to an exemplary embodiment. Figure 2A is an upper perspective view of a CAD model of the trolley 20 and Figure 2B is an upper, rear perspective view. Figures 2A to 2B also depict a cable 2100 according to an exemplary embodiment providing a running surface for the trolley 20, having a tether 2101 , for example an intermediary securing such as a guy for the cable, extending transversely away therefrom.

The trolley 20 is for a zip line, the trolley 20 comprising: a frame 201 comprising a channel 210, defining a longitudinal axis Z, having an open side 211 and adapted to be received on a cable 2100 of the zip line; and a first set of projections 221 , including a first projection 221 A and a second projection 221 B, coupled to the frame 201 and mutually spaced apart along the longitudinal axis Z, wherein the trolley 20 is retained on the cable 2100 by the first set of projections 221 projecting across the open side 211 and wherein the first set of projections 221 provides a bearing surface B for supporting the trolley 20 on the cable 2100; wherein the first set of projections 221 is arrangeable in: a first arrangement, wherein the first projection 221 A and the second projection 221 B cantilever across the open side 211 ; and a second arrangement, wherein the first projection 221 A or the second projection 221 B cantilevers across the open side 211 ; wherein the trolley 20 is arranged to move from the first arrangement to the second arrangement by a force F applied on the first set of projections 221 .

The trolley 20 is generally as described with respect to the trolley 10, description of which is not repeated for brevity.

In this example, the trolley 20 comprises a second set of projections 222, including a first projection 222A and a second projection 222B.

In this example, the second set of projections 222 is freely rotatably coupled to the frame 201 , having a rotational axis orthogonal to the longitudinal axis Z. In this example, the trolley 20 comprises a second hub 232, freely rotatably coupled to the frame 201 , wherein the second set of projections 222 extends therefrom radially. In this example, the second hub 232 has a rotational axis orthogonal to the longitudinal axis Z. In this example, the first hub 231 and the second hub 232 are mutually opposed across the open side 211. In this example, the first set of projections 221 and the second set of projections 222 mesh across the open side 211 .

In contrast to the trolley 10, in this example, the trolley 20 does not comprises a support configured to support a distal end of the first projection 221 A.

Figures 3A to 3F schematically depict a trolley 30 according to an exemplary embodiment. Figure 3A is a plan view of a CAD model of the trolley 30, Figure 3B is a front elevation view, Figure 3C is a lower plan view, Figure 3D is a side elevation view, Figure 3E is an upper, side perspective view and Figure 3F is a front, side perspective view.

The trolley 30 is for a zip line, the trolley 30 comprising: a frame 301 comprising a channel 310, defining a longitudinal axis Z, having an open side 311 and adapted to be received on a cable 3100 (not shown) of the zip line; and a first set of projections 321 , including a first projection 321 A and a second projection 321 B, coupled to the frame 301 and mutually spaced apart along the longitudinal axis Z, wherein the trolley 30 is retained on the cable 3100 by the first set of projections 321 projecting across the open side 311 and wherein the first set of projections 321 provides a bearing surface B for supporting the trolley 30 on the cable 3100; wherein the first set of projections 321 is arrangeable in: a first arrangement, wherein the first projection 321 A and the second projection 321 B cantilever across the open side 311 ; and a second arrangement, wherein the first projection 321 A or the second projection 321 B cantilevers across the open side 311 ; wherein the trolley 30 is arranged to move from the first arrangement to the second arrangement by a force F applied on the first set of projections 321 .

The trolley 30 is generally as described with respect to the trolley 20, description of which is not repeated for brevity.

In this example, the trolley 30 comprises a third set of projections 323, including a first projection 323A and a second projection 323B, and a fourth set of projections 324, including a first projection 324A and a second projection 324B, generally as described with respect to the first set of projections 321 and the second set of projections 322, respectively. In this example, the first set of projections 321 and the second set of projections 322 are mutually spaced apart along the longitudinal axis from the third set of projections 323 and the fourth set of projections In this example, the first set of projections 321 is freely rotatably coupled to the frame 301 , having a rotational axis oblique to the longitudinal axis Z. In this example, the trolley 30 comprises a third hub 333 and a fourth hub 334, generally as described with respect to the first hub 331 and the second hub 332, respectively.

In contrast to the trolley 20, in this example, the first set of projections 321 is rotatably coupled to the frame 301 , having a rotational axis oblique to the longitudinal axis. In more detail, in this example, the rotational axis is at an angle a~15° with respect to a vertical datum V. In this example, the first set of projections 321 is inclined at an angle /?~60° with respect to a vertical datum V. In this way, the first set of projections 321 is orthogonal to the vertical datum V when contacting the cable 3100 while lift off from the cable and/or touch down onto the cable are improved since support of the trolley by the set of projections is gradually removed and/or gradually replaced.

In this example, the trolley 30 comprises a set of guides 350 disposed proximal and/or at an entrance and/or exit of the channel 310.

Figures 4A to 4B schematically depict a trolley 40 according to an exemplary embodiment. Figure 4A is an upper, side perspective view of a CAD model of the trolley 40 and Figure 4B is a plan view.

The trolley 40 is for a zip line, the trolley 40 comprising: a frame 401 comprising a channel 410, defining a longitudinal axis Z, having an open side 411 and adapted to be received on a cable 4100 (not shown) of the zip line; and a first set of projections 421 , including a first projection 421 A and a second projection 421 B, coupled to the frame 401 and mutually spaced apart along the longitudinal axis Z, wherein the trolley 40 is retained on the cable 4100 by the first set of projections 421 projecting across the open side 411 and wherein the first set of projections 421 provides a bearing surface B for supporting the trolley 40 on the cable 4100; wherein the first set of projections 421 is arrangeable in: a first arrangement, wherein the first projection 421 A and the second projection 421 B cantilever across the open side 411 ; and a second arrangement, wherein the first projection 421 A or the second projection 421 B cantilevers across the open side 411 ; wherein the trolley 40 is arranged to move from the first arrangement to the second arrangement by a force F applied on the first set of projections 421 . The trolley 40 is generally as described with respect to the trolley 30, description of which is not repeated for brevity.

In this example, the first hub 431 , the second hub 432, the third hub 433 and the fourth hub 434 are alternately staggered along the longitudinal axis, with respect to the open side 411 .

In this example, the trolley 40 does not comprise a set of guides.

Figure 5 schematically depicts a trolley 50 according to an exemplary embodiment. Figure 5 is an upper, side perspective view of a CAD model of the trolley 50. Figure 5 also depicts a cable 5100 according to an exemplary embodiment providing a running surface for the trolley 50, having a tether 5101 , for example an intermediary securing such as a guy for the cable, extending transversely away therefrom.

The trolley 50 is for a zip line, the trolley 50 comprising: a frame 501 comprising a channel 510, defining a longitudinal axis Z, having an open side 511 and adapted to be received on a cable 5100 of the zip line; and a first set of projections 521 , including a first projection 521 A and a second projection 521 B, coupled to the frame 501 and mutually spaced apart along the longitudinal axis Z, wherein the trolley 50 is retained on the cable 5100 by the first set of projections 521 projecting across the open side 511 and wherein the first set of projections 521 provides a bearing surface B for supporting the trolley 50 on the cable 5100; wherein the first set of projections 521 is arrangeable in: a first arrangement, wherein the first projection 521 A and the second projection 521 B cantilever across the open side 511 ; and a second arrangement, wherein the first projection 521 A or the second projection 521 B cantilevers across the open side 511 ; wherein the trolley 50 is arranged to move from the first arrangement to the second arrangement by a force F applied on the first set of projections 521 .

The trolley 50 is generally as described with respect to the trolley 40, description of which is not repeated for brevity.

In this example, the first set of projections 521 is freely rotatably coupled to the frame 501 , having a rotational axis orthogonal to the longitudinal axis Z. In this example, the first projection 521A is a non-rolling projection and the bearing surface B is a plain bearing surface. In this example, the first projection 521 A comprises a projection having a non-constant crosssection, having a relatively larger distal end. In this example, the first set of projections 521 includes 8 projections. In this example, the first set of projections 521 and the second set of projections 522 do not mesh across the open side 511 .

Figures 6A to 6B schematically depict a bracket 65 according to an exemplary embodiment. Figure 6A is a lower, front perspective view of a CAD model of the bracket 65 and Figure 6B is a rear perspective view.

The bracket 65 is for a cable C (a conventional cable having no tethers c.f. a tether according to the second aspect) for a zip line, the bracket 65 comprising: a frame 601 comprising a channel 610, defining a longitudinal axis Z, having an open side 611 and adapted receive the cable C of the zip line; and a first set of projections 621 , including a first projection 621 A and a second projection 621 B, coupled to the frame and mutually spaced apart along the longitudinal axis Z, wherein the cable C is retained in the channel 610 by the first set of projections 621 projecting across the open side 611 and wherein the first set of projections 621 provides a bearing surface B for supporting the cable C thereupon; wherein the first set of projections 621 is arrangeable in: a first arrangement, wherein the first projection 621 A and the second projection 621 B cantilever across the open side 611 ; and a second arrangement, wherein the first projection 621 A or the second projection 621 B cantilevers across the open side 611 ; wherein the bracket is arranged to move from the first arrangement to the second arrangement by a force F applied on the first set of projections 621 .

The bracket 65 is generally as described with respect to the trolley 20 mutatis mutandis, description of which is not repeated for brevity.

In this example, obstacles O1 and 02 are respectively a freely-rolling pulley of a conventional trolley and a safety loop pulled thereby. Upon encountering or contacting the first and second sets of projections 621 , 622 supporting the cable C, the obstacles O1 and 02 in turn move the bracket from the first arrangement to the second arrangement by rotating the sets of projections 621 , 622 on their respective hubs 631 , 632, thereby maintaining support of the cable C while allowing the obstacles O1 and 02 to move therepast.

Figure 7 schematically depicts a trolley 70 according to an exemplary embodiment. Figure 7 is a front elevation view of a CAD model of the trolley 70.

The trolley 70 is for a zip line, the trolley 70 comprising: a frame 701 comprising a channel 710, defining a longitudinal axis Z, having an open side 711 and adapted to be received on a cable 7100 (not shown) of the zip line; and a first set of projections 721 , including a first projection 721 A and a second projection 721 B, coupled to the frame 701 and mutually spaced apart along the longitudinal axis Z, wherein the trolley 70 is retained on the cable 7100 by the first set of projections 721 projecting across the open side 711 and wherein the first set of projections 721 provides a bearing surface B for supporting the trolley 70 on the cable 7100; wherein the first set of projections 721 is arrangeable in: a first arrangement, wherein the first projection 721 A and the second projection 721 B cantilever across the open side 711 ; and a second arrangement, wherein the first projection 721 A or the second projection 721 B cantilevers across the open side 711 ; wherein the trolley 70 is arranged to move from the first arrangement to the second arrangement by a force F applied on the first set of projections 721 .

The trolley 70 is generally as described with respect to the trolley 30, description of which is not repeated for brevity.

In contrast to the trolley 30, in this example, the first set of projections 721 is rotatably coupled to the frame 701 , having a rotational axis orthogonal to the longitudinal axis. In more detail, in this example, the rotational axis is at an angle a = 0° with respect to a vertical datum V. In this example, the first set of projections 721 is inclined at an angle /?~60° with respect to a vertical datum V. In this way, the first set of projections 721 is at the angle /?~60° to the vertical datum V when contacting the cable 7100 while lift off from the cable and/or touch down onto the cable are improved since support of the trolley by the set of projections is gradually removed and/or gradually replaced.

Although a preferred embodiment has been shown and described, it will be appreciated by those skilled in the art that various changes and modifications might be made without departing from the scope of the invention, as defined in the appended claims and as described above.

Attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.

All of the features disclosed in this specification (including any accompanying claims and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at most some of such features and/or steps are mutually exclusive.

Each feature disclosed in this specification (including any accompanying claims, and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

The invention is not restricted to the details of the foregoing embodiment(s). The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.