EP4705142A1 - Clamp with first and second closed positions - Google Patents

Abstract

According to various, but not necessarily all, embodiments of the invention there is provided a clamp (100) configured to connect a pair of elongate articles (2, 3, 5), the clamp comprising: a first closed position to secure the clamp (100) to a first one of the elongate articles (2, 3); and a second closed position to further secure the clamp (100) to a second one of the elongate articles (5).

Description

CLAMP WITH FIRST AND SECOND CLOSED POSITIONS

FIELD OF THE INVENTION

Embodiments of the present invention relate to a clamp with first and second closed positions. In particular, but not exclusively, they relate to a jumper clamp for a catenary system.

BACKGROUND TO THE INVENTION

Jumpers are electrically conductive wires that electrically interconnect electrical wires, terminals, or electrodes.

Jumpers have a defined purpose in the context of catenary systems for vehicles such as trains, trams, or trolleybuses. Jumpers are flexible, un-tensioned conductive lines that are used to ensure that electrical continuity is provided at overlaps between tension lengths (wire runs) of contact lines and/or catenary lines (messenger lines). Jumpers can further ensure that all wire run sections are at the same electrical potential. In catenary systems that do not have current-carrying droppers, a jumper can provide electrical current sharing between the contact line and the catenary line (messenger line). A dropper is a vertical tensioned line for suspending the contact line from the catenary line.

Various types of clamps are used to connect elongate articles to each other. In the context of jumpers, clamps can connect the jumper to the catenary line and to the contact line.

A ‘parallel groove’ (PG) clamp is an example of a clamp that can connect an untensioned elongate article to a tensioned elongate article. A pair of plates are connected to each other by a nut and bolt, and are shaped to define a pair of grooves therebetween. Once the elongate articles are trapped in the grooves, the nut and bolt can be tightened to move the plates together and provide a rigid connection. An ‘ampact(TM) wedge’ connector is another example of such a clamp. A wedge is driven into a C-shaped sleeve, trapping the elongate articles between the wedge and the sleeve.

Both types of clamp require the use of tools to engage. If a worker drops a tool while working on a catenary system, the falling tool can present a hazard.

Further, the installation time can be significant. The fitting of a PG clamp has been found to take around 46 seconds by a skilled worker.

Further, two different shapes of PG clamps are needed for jumpers. A first shape of PG clamp is used to connect the jumper to side grooves of a contact line. A second shape of PG clamp is used to connect the jumper to the catenary line, because catenary lines have a different shape than contact lines.

The requirement to use tools, the installation time, and the requirement for multiple shapes of clamp, are not generally recognised as problems because nearly all jumper clamps look and function the same as PG clamps, and have done for many years.

BRIEF DESCRIPTION OF VARIOUS EMBODIMENTS OF THE INVENTION

According to various, but not necessarily all, embodiments of the invention there is provided a clamp configured to connect a pair of elongate articles, the clamp comprising: a first closed position to secure the clamp to a first one of the elongate articles; and a second closed position to further secure the clamp to a second one of the elongate articles.

According to various, but not necessarily all, embodiments of the invention the clamp comprises: clamping members (e.g., clamping legs); a bias urging a pair of the clamping members towards the first closed position to secure the clamp to the first elongate article; and a fastener arrangement to actuate the clamping members towards a second closed position to further secure the clamp to the second elongate article.

The bias provides the advantage that the user can let go of the clamp and the clamp will stay secured to the first elongate article. This frees up the user’s hands to manipulate the second elongate article into position and then operate the fastener arrangement (fastener or fasteners). No tools are required to secure the clamp to the first elongate article. The installation time is also reduced. If the fastener is the later- described hand-operable latch, the overall installation time may be less than 10 seconds and completely tool-free.

The pair of elongate articles may be electrical conductors. The pair of elongate articles may be wires. The clamp may be configured to electrically and mechanically connect the pair of elongate articles.

The pair of elongate articles may be overhead lines of a catenary system. The clamp may therefore be categorised as an overhead line clamp.

The pair of overhead lines of the catenary system may comprise a jumper, and either a contact line or a catenary line. The clamp may therefore be categorised as a jumper clamp.

The clamp may be compatible with both the contact line and the catenary line, despite them having different cross-section shapes. An advantage is that the clamp has a single standardised shape.

The pair of elongate articles may comprise a tensioned line and an un-tensioned line. The un-tensioned line may be the jumper. The tensioned line may be the contact line or the catenary line. The jumper may be a current-carrying jumper for electrically interconnecting a pair of the contact lines and a pair of the catenary lines. Alternatively, the jumper may be an equipotential jumper for electrically interconnecting the contact line and a pair of the catenary lines. Alternatively, the jumper may be a C-jumper for electrically interconnecting the contact line to the catenary line.

The jumper may be a stranded wire. The catenary line may be a stranded wire. The contact line may be a drawn wire.

The contact line may have a rounded perimeter comprising side grooves. The jumper may have a substantially circle-shaped perimeter. The catenary line may have a substantially circle-shaped perimeter.

At the second closed position, the clamping members may be simultaneously secured to the substantially circle-shaped perimeter of the jumper, and either the side grooves of the contact line or the substantially circle-shaped perimeter of the catenary line.

The clamping members at the second closed position may be configured to secure the first and second elongate articles substantially parallel to each other.

The clamping members at the second closed position may be configured to secure the first and second elongate articles at a separation of approximately 35mm or more, measured from centre-to-centre of the first and second elongate articles.

The clamp may have a first end and a second opposite end.

The pair of clamping members at the first closed position may be configured to clamp the first elongate article therebetween, at or proximal to the first end of the clamp.

The clamping members at the second closed position may be further configured to clamp the second elongate article therebetween, at or proximal to the second end of the clamp. Therefore, at the second closed position, the clamping members may be configured to simultaneously clamp the first and second elongate articles therebetween.

The clamping members at the second closed position may be configured to clamp the second elongate article substantially parallel to the first elongate article.

The clamping members actuated by the fastener arrangement may be the pair of clamping members. Therefore, at the second closed position, the pair of clamping members may be secured to the first and second elongate articles. The clamp may comprise no more clamping members than the pair of clamping members.

Each of the pair of clamping members may have a first end, the first ends being at the first end of the clamp. Each of the pair of clamping members may have a second opposite end, the second ends being at the second end of the clamp.

At the first closed position, the first ends of the pair of clamping members may be closer to each other than the second ends of the pair of clamping members, enabling the first elongate article to be clamped at or proximal to the first ends of the clamping members.

At the second closed position, the second ends of the pair of clamping members may be closer to each other than the second ends are in the first closed position, enabling the second elongate article to be clamped at or proximal to the second ends of the clamping members.

At the first closed position, the pair of clamping members may be splayed out relative to each other. At the second closed position, the pair of clamping members may be more parallel relative to each other than in the first closed position.

At the second closed position, the pair of clamping members may be substantially parallel relative to each other. The degree to which the pair of clamping members are parallel may depend on any differences in the cross-sections of the pair of elongate articles. The bias may be configured to apply bias force at a location between the first and second ends of the pair of clamping members. The bias may urge the first ends towards each other. The bias may urge the second ends away from each other.

The bias may urge the pair of clamping members from an open position towards the first closed position. The bias may urge the one end of the clamp closed (the first end). At the open position, corresponding ends of the pair of clamping members may be separated to enable the first elongate article to be received between the corresponding ends. The corresponding ends may define a mouth therebetween for receiving the first elongate article. The corresponding ends may be the first ends of the pair of clamping members referred to above.

At the open position, the corresponding ends of the pair of clamping members may be further apart from each other than when the pair of clamping members are at the first closed position, to enable the first elongate article to be received between the corresponding ends.

At the first closed position, the corresponding ends of the pair of clamping members may be close enough to each other for the bias to secure the first elongate article between the pair of clamping members.

The pair of clamping members may be actuatable from the first closed position to the open position by actuation against a force of the bias. The actuation may separate the corresponding ends of the pair of clamping members to enable the first elongate article to be received between the corresponding ends.

A position of the actuation may be at or proximal to opposite ends of the pair of clamping members, opposite the corresponding ends. The opposite ends may be the second ends of the pair of clamping members referred to earlier.

The actuation to the open position may comprise squeezing the pair of clamping members together at the position at or proximal to the opposite ends of the pair of clamping members. The bias may have a stiffness low enough that the actuation can be effected by a user’s digits, such as a thumb and fingers, to actuate the pair of clamping members to the open position. The clamp can therefore be defined as a hand-operable clamp. The clamp may be hand-actuatable between the open position and the first closed position.

The fastener arrangement may have discrete states including an unlocked position and a locked position. This obviates the need for a torque specification for the user to manually check and adhere to.

The fastener arrangement may be in the unlocked position when the clamp is open for receiving the first elongate article. The clamping members may be in the open position described above. The fastener arrangement may be in the unlocked position when the pair of clamping members are at the first closed position securing the first elongate article. The fastener arrangement may be in the locked position when the clamping members are at the second closed position.

The fastener arrangement may move the pair of clamping members from the first closed position to the second closed position, when the fastener arrangement is moved/tightened from the unlocked position to the locked position.

The fastener arrangement may be configured to actuate (force) the clamping members towards each other. The fastener arrangement may be configured to actuate the clamping members towards each other when the fastener arrangement is moved from the unlocked position to the locked position. This may make the clamping members more parallel as described earlier.

While the fastener arrangement is at the unlocked position, the clamping members may be openable to receive the first elongate article therebetween, then releasable to enable the bias to move the pair of clamping members to the first closed position to secure the first elongate article while the second elongate article is inserted between the clamping members. When the fastener arrangement is moved to the locked position, the fastener arrangement may move the clamping members closer together to further secure the second elongate article therebetween such that both the first and second elongate articles are simultaneously clamped.

The fastener arrangement may comprise a hand-operable latch. The hand-operable latch provides the advantage of enabling rapid securing of the elongate articles, and for rapid adjustment of the clamp position to correct the positioning of the elongate articles. This is because the hand-operable latch obviates the requirement for tools. The clamp can therefore be described as hand-actuatable between the first and second closed positions, via the fastener arrangement.

The hand-operable latch may comprise a hand-operable lever. One end of a stroke of the hand-operable lever may define the unlocked position of the fastener arrangement. An opposite end of the stroke of the hand-operable lever may define the locked position of the fastener arrangement. Rotating the hand-operable lever towards the locked position may translate and/or rotate move the clamping members closer together. The clamping members may be forced together to become more parallel to each other and to simultaneously clamp the pair of elongate articles.

The fastener arrangement may define a bistable latch mechanism. For example, the hand-operable latch may be an over-centre latch. The over-centre latch may comprise the hand-operable lever configured to rotate a cam to actuate the clamping members.

An advantage is that toggle-like feedback is provided to the user, indicating that the clamping members are at the second closed position. This obviates the need for a torque specification for the user to manually check and adhere to.

The fastener arrangement may comprise a shaft extending through apertures in the clamping members, connecting the hand-operable latch at one end of the shaft with an anchor (e.g., nut) at the other end of the shaft. The clamping members may be slidable towards or away from each other along the shaft. The shaft may enable the pair of clamping members to splay out relative to each other, in the first closed position. The shaft and the apertures may be shaped to secure the clamping members and fastener arrangement in a fixed orientation relative to the shaft. This advantageously prevents the fastener arrangement from rotating, meaning it is always in the correct orientation and leaves no room for user error. The shaft and the apertures may be noncircular in cross-section shape, to enable the fixed orientation.

The fastener arrangement may further comprise a catch that is engageable when the clamping members are at the second closed position, to inhibit movement of the clamping members away from the second closed position.

An advantage is that the fastener arrangement is resistant against being worked loose, for example as a result of noise, vibration and harshness of passing vehicles, or wind- induced oscillation of the line, among other things.

The catch may automatically (without user intervention) engage when the fastener arrangement reaches the locked position. The catch may be a snap-fit catch. The catch may be hook-shaped. The catch may be shaped to engage with one of the clamping members.

The fastener arrangement may be mounted against one of the clamping members and the catch may be shaped to engage with another of the clamping members. The fastener arrangement may be mounted against one of the pair of clamping members and the catch may be shaped to engage with another of the pair of clamping members.

The catch may be shaped to cover one of the ends of the clamp. The catch may be shaped to cover the second end of the clamp.

The catch may be shaped to cover a gap between the clamping members. Each end of the gap may comprise a mouth through which a corresponding one of the pair of elongate articles is received. The mouths may include the mouth referred to earlier. The catch may be shaped to cover one of the mouths. The mouth may be at the second end of the clamp. The mouth may be defined between the second ends of the clamping members. The catch may therefore cover the second ends of the clamping members to cover the second elongate article.

An advantage of the catch covering the second ends of the clamping members is that the catch further prevents the bias from moving the second ends apart, and further encloses the second elongate article.

In this example, the first elongate article may be the contact line and the second elongate article may be the jumper, or the first elongate article may be the jumper and the second elongate article may be the catenary line. In other words, the catch does not cover the contact line. An advantage is that the contact line remains uncovered to enable a continuous connection between the contact line and a vehicle power collector such as a pantograph.

The catch may be supported by the hand-operable lever. The catch may be supported by an end of the hand-operable lever. The catch may be cantilevered from the hand- operable lever.

In other examples, the hand-operable lever may have an axis of rotation extending perpendicularly or mostly perpendicularly to an upstream-downstream direction of the clamp. The hand-operable lever may therefore be rotatable in the upstream or downstream direction. The upstream-downstream direction may be the direction in which the elongate articles extend through the clamp, in-use.

The catch may be engageable with an upstream end or downstream end of the same clamping member to which the fastener arrangement is mounted.

The clamping members may be in the form of plates.

Each clamping member may be substantially rotationally symmetrical. Each clamping member may have Order 2 rotational symmetry. This enables a single part design to be used for both clamping members. This means that the clamping members cannot be mis-assembled, which benefits assembly and costs. The clamp may comprise electrically conductive material to form an electrical connection between the first and second elongate articles. The clamping members may be formed from the electrically conductive material such as copper, silver, tin, aluminium, or an alloy thereof.

The clamping members may comprise pincer formations (pincers) shaped to fit within grooves of one of the pair of elongate articles. The grooves may be the side grooves of the contact line.

The clamping members may have pincer-shaped ends to define the pincer formations. The pincer-shaped ends may each comprise an edge shaped to fit within a corresponding one of the contact-line side grooves.

The pincer-shaped ends may be the first ends referred to earlier. The first ends of the clamping members may therefore be connectable to the first elongate article, where the first elongate article comprises the grooves. The first elongate article may be the contact line comprising the side grooves.

In some examples, the second ends of the clamping members may also be pincershaped ends. The second ends of the clamping members may therefore also be connectable to the side grooves of the contact line, assuming that the optional catch is modified or omitted to avoid covering the contact line.

The clamping members may define a first channel to receive at least part of one of the elongate articles. The first channel may be a rounded channel. Each of the pair of clamping members may define a portion of the first channel. For example, each of the pair of clamping members may have a first section defining a respective portion of the first channel. The first sections may comprise rounded curves/bends to define the portions of the first channel.

The first channel may be located proximal to one end of the clamp. The first channel may be located proximal to the first end of the clamp. The pair of clamping members may define the first channel to receive the first elongate article. The first channel may be located proximal to ends of the clamping members, such as the first ends. The first channel may be shaped to receive the first elongate article.

When the first elongate article comprises a jumper, the first channel may enable the jumper to be seated substantially within the first channel. When the first elongate article comprises a catenary line, the first channel may enable the catenary line to be seated substantially within the first channel. When the first elongate article comprises a contact line, the contact line may be seated within a channel mouth of the first channel and mostly outside the first channel. The channel mouth may be one of the mouths referred to earlier.

The clamping members may define a second channel to receive at least part of the other of the elongate articles. The second channel may be opposite the first channel. The second channel may be located proximal to an opposite end of the clamp. The first channel may be located proximal to the second end of the clamp. The pair of clamping members may further define the second channel to receive the second elongate article. The second channel may be located proximal to the second ends of the pair of clamping members.

The first and second channels may be located towards opposite ends of the same gap between the clamping members. The second channel may be substantially parallel to the first channel. The second channel may be approximately 35mm from the first channel, or more.

The second channel may be a rounded channel. Each of the pair of clamping members may define a portion of the second channel. For example, each of the pair of clamping members may have a second section defining a respective portion of the second channel. The second sections may comprise rounded curves/bends to define the portions of the second channel.

When the second elongate article comprises a jumper, the second channel may enable the jumper to be seated substantially within the second channel. When the second elongate article comprises the catenary line, the second channel may enable the catenary line to be seated substantially within the second channel. If the second channel is not covered by the optional catch, the second elongate article may comprise the contact line, wherein the contact line may be seated within a channel mouth of the second channel and mostly outside the second channel. The channel mouth may be one of the mouths referred to earlier.

Each of the pair of clamping members may comprise a middle section. The middle sections may be between the first and second sections, wherein the first and second sections may be shaped relative to the middle section to define the first and second channels.

The middle sections of the pair of clamping members may provide surfaces for mounting the bias. The middle sections of the pair of clamping members may be substantially parallel to each other. The middle sections of the pair of clamping members may be substantially flat. The middle sections of the pair of clamping members may each comprise an aperture through which the shaft of the fastener arrangement can extend.

The clamp may provide a spacer in the gap between the clamping members, to provide a minimum centre-to-centre distance between the pair of elongate articles. The spacer may be sized to provide the minimum centre-to-centre distance at a value of 35mm or more.

The spacer may be located between the middle sections of the pair of clamping members. Opposite ends of the spacer may be aligned with perimeters of the first and second channels.

The bias may be in the form of a spring, such as a V-spring. Each end of the spring may act as a stop to prevent the elongate articles from being inserted beyond the first and second channels. Therefore, the spacer may be defined by the bias, rather than being a separate part. One end of the spacer may be defined by a hinge of the bias, and the other end of the spacer may be defined by an angled tip of the bias. The angled tip of the bias may extend from one of the pair of clamping members towards the other of the pair of clamping members.

The bias may be between the pair of clamping members. The bias may be located between the middle sections of the pair of clamping members.

The bias may be in the form of a spring, such as a V-spring. The spring may comprise a pair of spring legs connected to each other at a hinge. One of the spring legs may bias against one of the pair of clamping members while the other of the spring legs may bias against the other of the pair of clamping members. The spring legs may extend substantially parallel to the pair of clamping members.

The hinge of the bias may define one end of the spacer as described above. One of the spring legs of the bias may comprise the angled tip defining the other end of the spacer, as described above.

The bias may be secured to the pair of clamping members by the shaft of the fastener arrangement. Each spring leg of the bias may have a corresponding aperture therethrough, through which the shaft of the fastener arrangement can extend.

According to various, but not necessarily all, embodiments of the invention there is provided a catenary system comprising a pair of the clamps, and a set of elongate articles.

The set of elongate articles may comprise the jumper, the contact line, and the catenary line.

One of the clamps may connect the jumper to the contact line, in the second closed position. The contact line may be the first elongate article and the jumper may be the second elongate article. The other of the clamps may connect the jumper to the catenary line, in the second closed position. The jumper may be the first elongate article and the catenary line may be the second elongate article, or vice versa.

Each clamping member may have a structurally-reinforcing variable cross-section geometry from its upstream end to its downstream end. The structurally-reinforcing variable cross-section geometry may comprise variations in shape of the respective clamping member.

At least one of the clamping members may comprise one or more bends in a downstream direction from its upstream end to its downstream end.

The one or more bends may comprise a bend defining a flared upstream portal and/or a bend defining a flared downstream portal.

The clamp may comprise approximately-conically flared entrances and/or exits for the first and/or second elongate articles.

The one or more bends may comprise bends defining a raised section of the clamping member therebetween, the raised section comprising an aperture through which the shaft of the fastener arrangement extends.

BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of various examples of embodiments of the present invention reference will now be made by way of example only to the accompanying drawings in which:

FIG. 1 illustrates an example of a catenary system;

FIG. 2 illustrates a cross-section of a contact line;

FIG. 3 illustrates a perspective view of an example clamp;

FIG. 4 illustrates a side view of the clamp in a first closed position;

FIG. 5 illustrates a side view of the clamp in a second closed position; FIG. 6 illustrates a perspective view of another example clamp;

FIG. 7 illustrates a perspective view of another example clamp; and

FIG. 8 illustrates a cross-section view of part of the clamp of FIG. 7.

DETAILED DESCRIPTION OF VARIOUS EMBODIMENTS OF THE INVENTION

FIG. 1 illustrates an example catenary system 1 for transportation. The illustrated catenary system 1 defines an electrified overhead line system for a vehicle power collector (e.g., pantograph) of a vehicle such as a train, tram, or trolleybus.

The catenary system 1 comprises tensioned lines including: an upper, catenary line 3; a lower, contact line 2; and periodically spaced droppers 4 suspending the contact line 2 from the catenary line 3.

The catenary system 1 further comprises un-tensioned lines in the form of jumpers 5. C-jumpers are shown, electrically connecting the catenary line 3 to the contact line 2. In this example, C-jumpers may be used when the droppers 4 are non-current carrying. However, in other examples, the jumpers 5 may be current-carrying jumpers or equipotential jumpers as defined earlier.

The contact line 2 is an electrically conductive line configured to contact the overhead device of the vehicle, forming an electrical connection. The contact line 2 is suspended at a substantially constant vertical height above the rails/roadway, to maintain constant contact with a vehicle power collector of the vehicle such as a pantograph, bow collector or trolley pole.

The catenary line 3 is an electrically conductive line attached at intervals to support structures such as masts or buildings. The catenary line 3 extends parallel to and above the contact line 2. The catenary line 3 droops at each mid-span, due to its own weight and the weight of the droppers 4 and contact line 2 suspended therefrom. The catenary line 3 can be a stranded wire of circular cross-section. The droppers 4 are upright electrically conductive lines, such as generally vertical wires, for hanging the contact line 2 from the catenary line 3. Droppers 4 which are connected to the mid-spans of the catenary line 3 are typically shorter than those connected towards the end spans of the catenary line 3, to compensate for the droop of the catenary line 3 and ensure that the contact line 2 is a constant height.

The jumpers 5 are flexible and connected to the lines 2, 3 in a curved manner to provide some slack. The bend radius of the jumper 5 at each connection may be approximately 150mm or more. The jumper 5 can be a stranded wire of circular cross-section.

The illustrated example system 1 is suitable for a heavy-rail implementation, over a permanent way. However, the clamp of the present invention is also useable in other types of catenary systems, such as a light rail/tram electrified overhead line system. The latter system may have spaced support lines perpendicular to the contact line 2, which connect to the contact line 2 directly or via a short dropper 4.

FIG. 2 illustrates an example of a cross-section of a contact line 2. Without limitation, the contact line 2 may be a single-core wire such as a cold drawn solid wire made of copper, silver, tin, or an alloy thereof, or another electrically conductive metal.

The contact line 2 has a rounded but non-circle cross-section. The contact line 2 has a curved base 22, a curved crown 24 (anvil), and side grooves 20 at its left and right sides. The side grooves 20 provide a clamping surface for clamps, enabling an interference clamping fit in which clamping members slot into the side grooves 20 and laterally compress the contact line 2.

The base 22 is uncovered and exposed for continuous contact with a vehicle power collector. The crown 24 is wider than the side grooves 20, so that when the contact line 2 is clamped it cannot be pulled out.

The exact dimensions of the contact line 2 may be standardised, but may differ globally depending on the railway standard applicable to the region. FIGS. 3-5 illustrate an example implementation of the clamp 100 according to various embodiments of the invention. The clamp 100 is a jumper clamp that can connect the jumper 5 to the contact line 2, and that can connect the jumper 5 to the catenary line

3. The clamp 100 is compatible with both the contact line 2 and the catenary line 3.

FIGS. 3 and 5 show a perspective view and a side view of the clamp 100 in the second closed position, while FIG. 4 shows a side view of the clamp 100 in the first closed position.

The clamp 100 comprises a pair of clamping members 102 in the form of electrically- conductive plates, acting as clamping legs of the clamp 100. The clamp 100 further comprises a bias 104, which is a V-spring in this example (pair of spring legs 144 connected at an acute hinge/fold 146). The clamp 100 further comprises a fastener arrangement in the form of a single fastener 106, which comprises a hand-operable latch 108 in this example. The hand-operable latch 108 comprises a hand-operable lever 112 having a catch 122 secured to its end.

The clamping members 102 and the bias 104 are mounted to a shaft 118 of the fastener 106. The shaft 118 interconnects a nut (or equivalent anchor 120) and the hand-operable latch 108, at opposite ends of the shaft 118. The clamping members 102, and spring legs 144 of the bias 104, comprise aligned through- hole apertures through which the shaft 118 extends. The shaft 118 and the apertures each have a Double-D shape (double-flat), to prevent the assembly from rotating about the shaft 118.

The clamping members 102 are secured between the anchor 120 and the hand- operable latch 108, with the bias 104 mounted in the central gap 124 between the clamping members 102.

The bias 104 urges the clamping members 102 into the splayed position shown in FIG.

4, analogous to a clothes peg (spring peg). This position is referred to herein as a first closed position. This enables the clamp 100 to hold on to a first elongate article, which is the contact line 2 in the illustrated example. This frees up both of the user’s hands to manipulate the second elongate article, in this example the jumper 5, into the clamp 100.

When the user has inserted the jumper 5 into the clamp 100, the user can then turn the hand-operable lever 112 through an obtuse or reflex angle, to force the clamping members 102 together into the second closed position shown in FIGS. 3 and 5, trapping the contact line 2 and the jumper 5 between the clamping members 102. Although not shown, the clamp 100 can also be used with the catenary line 3 instead of the contact line 2.

The contact line 2 and the jumper 5 are held apart from each other by the clamp 100, by a spacing of approximately 35mm (between wire centres), or another spacing required by the infrastructure owner.

Each clamping member 102 has a first end 114 and a second end 116 vertically opposite the first end 114. A clamp 100 that connects the jumper 5 to the contact line 2 is in an upright orientation so that the first end 114 is the bottom end and the second end 116 is the top end. This orientation holds the jumper 5 above the contact line 2, so that thejumper 5 cannot foul on vehicle power collectors. A clamp 100 that connects the jumper 5 to the catenary line 3 can be used either way up.

Each clamping member 102 is bent or formed into a shape that defines a variablewidth gap 124 between the clamping members 102. As a result, each clamping member 102 has a curved first section 136, a straight middle section 140, and a curved second section 138.

The middle sections 140 of the clamping members 102 are between the first and second sections 136, 138 and provide flat surfaces comprising the apertures for the shaft 118 of the fastener 106, as well as flat inner surfaces for the spring legs 144 of the bias 104 to urge against.

The curved first sections 136 of the clamping members 102 define a circular first channel 132 between said sections, and the curved second sections 138 of the clamping members 102 define a circular second channel 134 between said sections. The circular first and second channels 132, 134 extend in a parallel horizontal direction, parallel to the contact line 2. The circular first and second channels 132, 134 are each of a diameter large enough to hold the jumper 5 and the catenary line 3.

The bias 104 is located between the middle sections 140 of the clamping members 102 and acts as a spacer 142 between the first and second channels 132, 134, because the bias 104 extends as far as the perimeters of the first and second channels 132, 134. This ensures a minimum vertical spacing of the contact line 2 and the jumper 5. The hinge 146 of the bias 104 is at the perimeter of the first channel 132, and the end of one of the spring legs 144 is folded into an angled tip 148 that extends across the gap 124 and extends at least partially tangentially along the perimeter of the second channel 134.

The first channel 132 is open at the first ends 114 of the clamping members 102, and the second channel 134 is open at the second ends 116 of the clamping members 102. The gap between the first ends 114 of the clamping members 102, specifically between inner edges 130 of the first ends 114 of the clamping members 102, define a variablewidth first mouth 126 enabling access to the first channel 132. The corresponding gap between the inner edges 130 of the second ends 116 of the clamping members 102 define a variable-width second mouth 128 enabling access to the second channel 134.

The bias 104 can pivot the clamping members 102 about the shaft 118, and urges the first mouth 126 closed while urging the second mouth 128 open. To open the first mouth 126 wide enough to accept the contact line 2, the user squeezes the clamping members 102 at or near the second ends 116 of the clamping members 102, between their thumb and fingers. This flexes the clamping members 102, against the urging force of the bias 104, into an open position (not shown) at which the first ends 114 of the clamping members 102 are separated by a large enough distance that the crown 24 of the contact line 2 is insertable into the first channel 132 through the wider first mouth 126. The user aligns the side grooves of the contact line 2 with the sides of the first mouth 126, which are the inner edges 130 of the first ends 114 of the clamping members 102. The user then releases their squeezing force. This enables the bias 104 to urge the inner edges 130 of the first ends 114 of the clamping members 102 against the side grooves of the contact line 2. This traps the contact line 2 in the first mouth 126 of the clamp. This represents the first closed position of the clamping members 102.

The crown 24 of the contact line 2 (above the side grooves) protrudes slightly into the first channel 132. The crown 24 of the contact line 2 is wider than the side grooves. Therefore, the clamp 100 cannot be pulled off the contact line 2. The base 22 of the contact line 2 is exposed to form a continuous uncovered connection to a vehicle power collector.

The inner edges 130 of the first ends 114 of the clamping members 102 have an internal angle (e.g., 90 degrees) matching the internal angle of the V-shaped side grooves, to function as pincer formations. This enables the first ends 114 of the clamping members 102 to act as pincer-shaped ends that snugly fit in the side grooves of the contact line 2.

Once the clamp 100 is holding the contact line 2 in the first channel 132, the clamping members 102 in the first closed position may still be slightly splayed out such that the second mouth 128 is wide enough to accept the jumper 5. The user lowers the jumper 5 through the second mouth 128 into the second channel 134. The angled tip 148 of one of the spring legs 144 of the bias 104 prevents the jumper 5 from being inserted beyond the second channel 134 into the space between the middle sections 140 of the clamping members 102. In some examples, the user may have the alternative choice of axially sliding an end of the jumper 5 into the second channel 134.

Once the jumper 5 is positioned within the second channel 134, the user can rotate the hand-operable lever 112 from the unlocked position of FIG. 4 to the locked position of FIG. 5, to engage the hand-operable latch 108. The stroke length of the hand- operable lever 112 may be an obtuse or reflex angle. The illustrated hand-operable latch 108 comprises a cam 110 connected to the hand- operable lever 112. The hand-operable latch 108 exhibits bistability, toggling between stable positions as it is moved ‘over-centre’ of the cam 110.

The hand-operable lever 112 has a mechanical advantage of greater than two or greater than three or greater than four. As the hand-operable lever 112 is rotated, the cam 110 pushes one clamping member 102 towards the other along the shaft 118. This causes the clamping members 102 to become more parallel from their previous splayed orientations. The hand-operable lever 112 is able to travel at least a short distance past the over-centre position (maximum lift of the cam 110), to settle in a stable locked position.

Specifically, as the hand-operable lever 112 is rotated to the locked position, the second ends 116 of the clamping members 102 are brought together until the second mouth 128 therebetween is less wide than the diameter of the jumper 5. This traps the jumper 5 within the second channel 134. Meanwhile, the crown 24 of the contact line 2 is trapped within the first channel 132 between the pincer formations (inner edges 130 of the first ends 114 of the clamping members 102). This defines the second closed position (FIG. 5) of the clamping members 102, where the clamping members 102 trap both the contact line 2 and the jumper 5 therebetween.

To provide further security, a distal end of the hand-operable lever 112 supports an optional hook-shaped snap-fit catch 122, which is shaped to cover the second mouth 128 and snap-fit to the second section 138 of the clamping member 102 on the opposite side of the gap 124. This prevents the hand-operable lever 112 from being worked loose and also covers the second channel 134. The catch 122 automatically engages with the hand-operable lever 108 reaches the locked position.

The catch 122 cannot be used to cover the contact line 2, to avoid interfering with. If the clamp 100 is used the wrong way up, the catch 122 will interfere with the base 22 of the contact line 2, preventing the catch 122 from engaging. FIGS. 4 and 5 only illustrate a clamp 100 holding a jumper 5 to a contact line 2. If the clamp 100 is instead holding the jumper 5 to the catenary line 3, then the orientation does not matter. The first and second channels 132, 134 would each receive one of the jumper 5 and the catenary line 3.

FIG. 6 illustrates a perspective view of another example clamp 100A, demonstrating that additional clamping members and fasteners may be provided.

The clamp 100A comprises a first clamping member 102A, a second clamping member 102B, and a third clamping member 102C.

The first channel 132 is defined between the first and second clamping members 102A, 102B. The second channel is defined between the first and third clamping members 102A, 102C. The channels 132, 134 of FIG. 6 are suitable for connecting a jumper 5 to a catenary line 3. A modified version of FIG. 6 may comprise pincer formations for compatibility with a contact line 2.

In FIG. 6, the fastener arrangement comprises a first fastener 106A and a second fastener 106B. The first fastener 106A secures the first and second clamping members 102A, 102B together to define a first closed position of the clamp 100A. In FIG. 6, a second fastener 106B secures the first and third clamping members 102A, 102C together to define the second closed position.

The first and second fasteners 106A, 106B are bolted fasteners rather than hand- operable latches. In other examples, hand-operable latches are used.

Without a bias, the first fastener 106A is instead used to hold the clamp 100A onto the first elongate article. If a bias is provided, it may urge a pair of the clamping members 102A-102B or 102A-102C towards a first closed position, in a similar manner to the clamp 100 of FIGS. 3-5. This enables the clamping members 102A, 102B to hold on to the first elongate article 5. The user can then lock the first fastener 106A and then secure the second elongate article to the other pair of clamping members 102A, 102C via the second fastener 106B. A second bias may optionally be provided for the other pair of clamping members 102A, 102C.

In other respects, the clamp 100A may have the same features as described in relation to FIGS. 3-5.

FIGS. 7-8 illustrates views of a further example clamp 100B, demonstrating several differences that can be implemented either individually or in combination.

The axis of rotation of the lever 112 is in a different direction than in the earlier FIGS, non-parallel with an upstream-downstream direction of the channels 132, 134 of the clamp 100. As a result, the catch 122 no longer covers the second channel 134. The axis of rotation is no longer transverse and is at least partially parallel to the channels 132, 134. If the clamp 100B is unintentionally inserted upside down such that the contact line 2 is in the second channel 134, the catch 122 will not interfere with the ability of the passing vehicle power collector to maintain continuous contact with the contact line 2.

As shown in FIG. 8, the catch 122 of the lever 112 of the clamp 100B can engage with an upstream end or downstream end of the middle section 140 of the same clamping member 102 to which the hand-operable latch 108 is mounted, the upstream and downstream ends of the middle section 140 being upright and extending between the curved sections 136, 138. In some examples, the catch 122 may be omitted.

A further modification in FIG. 7 is that each clamping member 102 has a structurally- reinforcing variable cross-section geometry from its upstream end to its downstream end. This relates to any variations in shape and/or thickness that increase the rigidity of the clamping member 102 against flexing about its minor axis. This provides resistance to pull-out forces. High pull-out forces may occur during installation, or in- use as a result of significant upwards thrusting of the catenary system 1 by passing vehicle power collectors. In examples, the structurally-reinforcing variable cross-section geometry is achieved by variations in shape without substantial variations in thickness. Each clamping member 102 comprises one or more bends in a downstream direction from its upstream end to its downstream end.

In FIG. 7, such bends define a flared upstream portal 150 and a flared downstream portal 152, formed in each clamping member 102.

Each flared portal 150, 152 may comprise a bend extending continuously or discontinuously between the first and second ends 114, 116.

In FIG. 7, the bend extends through the curved first section 136, through the middle section 140, and through the curved second section 138.

Where the flared portals 150, 152 intersect the curved sections 136, 138, approximately-conical flared entrances and exits for the lines 2, 5 are defined.

A further advantage of flaring at upstream and/or downstream ends is to tolerate some flexing of the lines 2, 5 as they enter or leave the clamp 100.

A further modification in FIG. 7 is the provision of bends 154 in the downstream direction in a central region of the middle section 140 of each clamping member 102.

The bends 154 have a raised section 156 (e.g. raised flat platform) therebetween, which is contacted by a washer 158 (e.g., saddle washer) of the hand-operable latch 108. The through-hole aperture through which the shaft 118 extends is located in the raised section 156.

During manufacture, if the assembler places one of the clamping members 102 facing the wrong direction (i.e., both facing the same way rather than facing each other), then the raised section 156 will instead be a sunken section. As a consequence, too much shank of the protruding shaft 118 will be exposed, so it will not be possible to properly assemble the hand-operable latch. Therefore, an advantage of the bends 154 is a reduced likelihood of incorrect assembly during manufacture, ensuring that the clamping members 102 are always assembled facing each other. A further advantage is that the bends 154 and raised section 156 provide reinforcement about the same axis as the flared portals 150, 152.

Although embodiments of the present invention have been described in the preceding paragraphs with reference to various examples, it should be appreciated that modifications to the examples given can be made without departing from the scope of the invention as claimed.

For example, it would be appreciated that the catch 122 is not limited to the specific example shown. It would also be appreciated that the hand-operable latch 108 may be replaced with a different type of fastener 106, including a nut and bolt fastener requiring a tool to operate. Other examples include, but are not limited to:

- a hand-operable crank such as a threaded screw with a hand-operable crank lever at one end;

- a rotary button clamp such as a quarter-turn clamp, a half-turn clamp or a full-turn clamp;

- a scissor mechanism clamp or other push-pull clamp.

Features described in the preceding description may be used in combinations other than the combinations explicitly described.

Although functions have been described with reference to certain features, those functions may be performable by other features whether described or not.

Although features have been described with reference to certain embodiments, those features may also be present in other embodiments whether described or not.

Whilst endeavouring in the foregoing specification to draw attention to those features of the invention believed to be of particular importance it should be understood that the Applicant claims protection in respect of any patentable feature or combination of features hereinbefore referred to and/or shown in the drawings whether or not particular emphasis has been placed thereon.

Claims

1. A clamp configured to connect a pair of elongate articles, the clamp comprising: a first closed position to secure the clamp to a first one of the elongate articles; and a second closed position to further secure the clamp to a second one of the elongate articles.

2. The clamp of claim 1 , in the form of an overhead line clamp, the pair of elongate articles being overhead lines of a catenary system.

3. The clamp of claim 1 or 2, wherein the clamp comprises electrically conductive material to form an electrical connection between the first and second elongate articles.

4. The clamp of any preceding claim, comprising: clamping members; a bias urging a pair of the clamping members towards the first closed position to secure the clamp to the first elongate article; and a fastener arrangement to actuate the clamping members towards the second closed position to further secure the clamp to the second elongate article.

5. The clamp of claim 4, wherein the clamping members at the second closed position are configured to secure the first and second elongate articles substantially parallel to each other.

6. The clamp of claim 4 or 5, wherein the clamping members at the second closed position are configured to secure the first and second elongate articles at a separation of approximately 35mm or more, measured from centre-to-centre of the first and second elongate articles.

7. The clamp of claim 4, 5, or 6, wherein the clamping members actuated by the fastener arrangement are the pair of clamping members, therefore, at the second closed position, the pair of clamping members are secured to the first and second elongate articles.

8. The clamp of any one of claims 4 to 7, wherein the clamp has a first end and a second opposite end, wherein each of the pair of clamping members has a first end, the first ends being at the first end of the clamp, wherein each of the pair of clamping members has a second opposite end, the second ends being at the second end of the clamp, wherein at the first closed position, the first ends of the pair of clamping members are closer to each other than the second ends of the pair of clamping members, enabling the first elongate article to be clamped at or proximal to the first ends of the clamping members, and wherein at the second closed position, the second ends of the pair of clamping members are closer to each other than the second ends are in the first closed position, enabling the second elongate article to be clamped at or proximal to the second ends of the clamping members.

9. The clamp of claim 8, wherein at the first closed position, the pair of clamping members are splayed out relative to each other, and wherein at the second closed position, the pair of clamping members are more parallel relative to each other than in the first closed position.

10. The clamp of claim 8 or 9, wherein the bias is configured to apply bias force at a location between the first and second ends of the pair of clamping members, wherein the bias urges the first ends towards each other, and wherein the bias urges the second ends away from each other.

11. The clamp of claim 8, 9, or 10, wherein the bias urges the pair of clamping members from an open position towards the first closed position, wherein the bias urges the first end of the clamp closed, wherein at the open position, the first ends of the pair of clamping members are separated to enable the first elongate article to be received between the first ends, wherein the first ends define a mouth therebetween for receiving the first elongate article.

12. The clamp of claim 11 , wherein the pair of clamping members are actuatable from the first closed position to the open position by actuation against a force of the bias, wherein the actuation separates the first ends of the pair of clamping members to enable the first elongate article to be received between the first ends, wherein a position of the actuation is at or proximal to the second ends of the pair of clamping members, opposite the first ends.

13. The clamp of claim 12, wherein the actuation to the open position comprises squeezing the pair of clamping members together at the position at or proximal to the second ends of the pair of clamping members.

14. The clamp of any one of claims 4 to 13, wherein the fastener arrangement has discrete states including an unlocked position and a locked position.

15. The claim of claim 14, wherein the fastener arrangement moves the pair of clamping members from the first closed position to the second closed position, when the fastener arrangement is moved from the unlocked position to the locked position.

16. The clamp of claim 14 or 15, wherein the fastener arrangement is configured to actuate the clamping members towards each other when the fastener arrangement is moved from the unlocked position to the locked position, which makes the clamping members more parallel to each other.

17. The clamp of claim 14, 15, or 16, wherein while the fastener arrangement is at the unlocked position, the clamping members are openable to receive the first elongate article therebetween, then releasable to enable the bias to move the pair of clamping members to the first closed position to secure the first elongate article while the second elongate article is inserted between the clamping members, wherein when the fastener arrangement is moved to the locked position, the fastener arrangement moves the clamping members closer together to further secure the second elongate article therebetween such that both the first and second elongate articles are simultaneously clamped.

18. The clamp of any one of claims 4 to 17, wherein the fastener arrangement comprises a hand-operable latch.

19. The clamp of claim 18, wherein the hand-operable latch comprises a hand- operable lever.

20. The clamp of claim 18 or 19, wherein the fastener arrangement comprises a shaft extending through apertures in the clamping members, connecting the hand- operable latch at one end of the shaft with an anchor at the other end of the shaft, and wherein the clamping members are slidable towards or away from each other along the shaft.

21. The clamp of any one of claims 4 to 20, wherein the fastener arrangement further comprises a catch that is engageable when the clamping members are at the second closed position, to inhibit movement of the clamping members away from the second closed position.

22. The clamp of any one of claims 4 to 21 , wherein the clamping members are in the form of plates.

23. The clamp of any one of claims 4 to 22, wherein the clamping members comprises pincer formations shaped to fit within grooves of one of the pair of elongate articles.

24. The clamp of any one of claims 4 to 23, wherein the clamp provides a spacer in a gap between the clamping members, to provide a minimum centre-to-centre distance between the pair of elongate articles.

25. A catenary system comprising a pair of the clamps each as defined in any one or more of claims 1 to 24, and a set of elongate articles, wherein the set of elongate articles comprises a jumper, a contact line, and a catenary line, wherein one of the clamps is operable to connect the jumper to the contact line, in the second closed position, and wherein the other of the clamps is operable to connect the jumper to the catenary line, in the second closed position.