Patent Description:
Many industries require transportation of goods and other materials from one location to another. Such transportation may be by road, rail, sea or air. For example, in the case of road transportation, goods (or other materials) may be transported by a vehicle such as a lorry or van that has a storage space (referred to hereinafter as a container) mounted to or supported on the chassis of the vehicle. Transportation of the goods constitutes a cost that must be borne by the entity transporting the goods. The cost includes, among others, the cost of paying the driver and the cost of fuel. To minimise these costs (among others) it is preferable to maximise use of the space available within containers.

One approach to maximising use of space is to provide adjustable horizontal beams within the container. The height of the beams with respect to the floor or deck of the container can be adjusted according to the size of the goods being transported to divide the vertical internal dimension of the container into two or more spaces. This enables goods to be stacked without loading goods directly on top of other goods. Use of such beams increases the potential for maximising use of the space but also requires the driver to be able to load and unload the goods at height.

The beams may comprise a box-section beam with two opposing box-shaped ends, each end coupled to a track mounted within the container.

The beams must be strong enough to support heavy goods; this may be, for example, up to <NUM>. Thus, the beams and the track are typically constructed from strong material such as metal.

In populated areas such as city centres, there may be noise limitations for deliveries made between certain times, such as <NUM>:00pm and <NUM>:00am. For example, deliveries made between <NUM>. 00pm and <NUM>. 00pm must not exceed 65dB, and deliveries between <NUM>. 00pm and <NUM>. 00am must not exceed 60dB.

In adjusting the height of the beams, and loading and/or unloading the cargo within the container, the noise created from the frictional contact and/or impact noise between the metal material of the decking beam and the track often exceeds the noise limitation in these populated areas.

<CIT> discloses a loading beam assembly for mounting on a track within a cargo vessel. <CIT> discloses a beam assembly for mounting on a track within a cargo unit. <CIT> discloses a mounting rail for aircrafts. <CIT> discloses a beam for securing cargo in a vehicle or the like, comprising a pivotable head portion and a latch bolt. <CIT> discloses double-decker rails arranged vertically along the inner walls of a container. The present invention seeks to avoid or mitigate the above-mentioned problems by providing a low noise decking system.

According to a first aspect, the invention provides an apparatus for coupling a beam to a track, comprising an arm assembly having a first end arranged to interface with the beam, and a second end opposite the first end, a head assembly coupled to the second end of the arm and arranged to engage with the track to inhibit movement of the head assembly along the track, wherein the head assembly comprises a receiving portion and a plastics material received within the receiving portion, characterised in that the receiving portion is a groove and the plastics material is a rod comprising a circular cross-section, and such that the plastics material provides a contact surface between the head assembly and the track when the head assembly is engaged with the track.

The coupling apparatus enables cargo to be suspended at height on decking beams coupled to a track within the internal walls of a container. When the cargo is required to be loaded and/or unloaded, the plastics material in contact with the track may reduce the noise created through frictional forces.

The head assembly may be rotatably coupled to the arm assembly. In some embodiments, the head assembly may be connected to the arm assembly by a pivot pin such that the head assembly is rotatable about an axis of rotation which extends through the pivot pin. The pivot pin may be secured with a locking nut.

The head assembly may be made of metal material, such as aluminium, steel or stainless steel. The track may comprise metal material such as aluminium, steel, or stainless steel. The plastics material may reduce metal on metal contact between the head assembly and the track to reduce the noise created when the metal head assembly is coupled to the metal track.

Materials such as plastics materials may have a lower coefficient of friction than metal material when it is in contact with other metal material. The plastics material may separate the head assembly and the track, reducing the noise created through frictional contact, and in particular noise created by metal on metal contact. The noise created through friction between the plastics material and the track may be lower than the noise created by metal in contact with metal, and may prevent noise exceeding the threshold at locations that have noise limitations.

The plastics material may comprise Acetal. The plastics material may comprise other plastic material such as polyvinyl chloride (PVC), high density polyethylene (HDPE), polypropylene (PP), or other plastics material known to the skilled person in the art. Over time, the plastics material may wear down through continued frictional contact with the track. Acetal plastic is advantageous as it is widely available and inexpensive to replace.

The receiving portion is a groove. The receiving portion may have a rounded shape configured to receive a cylindrical plastics material. In other embodiments, the receiving portion may be an elongated channel.

The plastics material is a rod. The plastics material may be a hollow rod. In some embodiments, the plastics material may be spherical, and the receiving portion may be correspondingly shaped.

The plastics material is a rod with a circular cross-section. A rod with a circular cross-section may reduce the surface contact with the track whilst retaining the separation between the head assembly and the track. The circular cross-section may potentially make movement easier through reduced frictional contact.

The plastics material may be secured in the receiving portion of the head assembly by adhesive, and/or mechanical fasteners such as clips or screws.

The head assembly may comprise two receiving portions, each receiving portion configured to receive a plastics material. The two receiving portions may be located to opposite sides of the head assembly. The plastics material in contact with the track may provide additional distance between the head assembly and the track. The plastics material may separate the head assembly from the track and reduce noise further. Advantageously, having two receiving portions and corresponding plastics material may reduce the frictional force on each independent plastics material, which may slow down the wearing down of the independent plastics material and reduce the number of times the plastics material is replaced though excess wear.

The head assembly may comprise a trigger mechanism. The trigger mechanism may enable the coupling assembly to engage with a receiver on the track, inhibiting any movement.

The trigger mechanism may be housed within the head assembly. The head assembly may hold the trigger mechanism such that a part of the trigger mechanism engages with a receiver on the track. In this configuration, the head assembly protects the trigger mechanism from external environmental effects such as weathering.

The trigger mechanism may comprise an actuator for operating the trigger mechanism. The trigger mechanism may comprise a first protrusion for engaging with a receiver on the track. The trigger mechanism may comprise a pivot pin for attaching the trigger mechanism to the head assembly and a biasing member, wherein the trigger mechanism is rotatable about the pivot pin and, in use, the biasing member urges against the trigger mechanism to engage the protrusion with the track.

The actuator may be a second protrusion extending away from the head assembly, the second protrusion comprising an aperture for receiving a receiving member. The receiving member may be a rod, bar or a hook. The receiving member may be used to manipulate the coupling apparatus when the beam and/or cargo is at a height.

The biasing member may be a tensioned wire. The biasing member may be a spring, for example a leaf spring or a coiled spring. The spring may be a double torsion spring, which advantageously applies a balanced force to the trigger.

The trigger mechanism may engage and/or disengage with the track. The first protrusion may engage with the track, such that the coupling apparatus is held stationary i.e. inhibited from moving. The trigger mechanism may be actuated to disengage the first protrusion with the track, such that the coupling apparatus is enabled to move along the track.

The trigger mechanism enables beams to be held stationary at height to securely store the cargo, particularly when transporting. This is advantageous when loading or unloading heavy cargo into the container to be supported by the beam.

The plastics material may remain in contact with the track when the head assembly moves along the track. When the trigger mechanism is actuated to disengage the first protrusion away from the track, the coupling apparatus may move along the track. The plastics material may remain in contact with the track such that the plastics material slides along the track and remains in contact with the track. Advantageously, the low friction plastics material enables the coupling apparatus to move (e.g. slide) along the track with ease. The plastics material may reduce the noise created when the coupling apparatus is moved along the track. The plastics material may reduce the surface area of the head assembly that contacts the track.

A portion of the plastics material may be exposed outwardly from the receiving portion and contact the surface of the track when the coupling apparatus is stationary and/or moving along the track. The portion of the plastics material exposed may be between <NUM>% and <NUM>% of the plastics material. A portion of the plastics material received by the receiving portion may be between <NUM>% and <NUM>% of the plastic material.

According to a second aspect of the invention there is provided a low-noise decking beam assembly comprising a track for mounting on a wall of a container, a beam having a first end and a second end, and a coupling apparatus for coupling a beam to a track in accordance with the first aspect of the invention, wherein the coupling apparatus is arranged to interface the first and/or second end of the beam and engage with the track.

The first and/or second end of the beam may each be interfaced with a coupling apparatus according to the first aspect of the invention.

According to an example, there may be a head assembly for coupling a beam to a track, the head assembly comprising a receiving portion and a plastics material received within the receiving portion, such that the plastics material provides a contact surface between the head assembly and the track when the head assembly is engaged with the track.

According to another example, there may be a track for a storage container comprising receiving apertures for receiving a coupling apparatus, and a plastics material arranged on a surface of the track, wherein the plastics material is a rod having a circular cross-section, and such that the plastics material provides a contact surface between the coupling apparatus and the track when the coupling apparatus is engaged with the track.

The track may be mounted on an internal wall of a container, and arranged to receive a coupling apparatus for coupling with a beam. The track mostly comprises of metal material such as aluminium or stainless steel, for example. This provides the track with strength and durability. The coupling apparatus may also comprise metal material such as aluminium or stainless steel, for example. The plastics material on the surface of the track may separate the track and the coupling apparatus. The noise created through friction between the plastics material and the coupling apparatus or impacts between the plastics material and the coupling apparatus may be lower than the noise created by metal in contact with metal, and may prevent noise exceeding the threshold at locations that have noise limitations.

The plastics material may be a flat contact surface. The plastics material may be a rod or bar aligned along the longitudinal axis of the track.

The track of the present embodiment may be configured to couple with any coupling apparatus as would reasonably be known to the skilled person. The track may be configured to receive a coupling apparatus according to the first aspect of the invention.

According to another aspect of the invention, there is provided a trigger bar for manipulating a trigger mechanism of a low-noise decking beam assembly according to the second aspect of the present invention, the trigger bar comprising an elongated arm comprising a first end and a second end opposite the first end, and an actuating assembly connected to the second end of the arm. The actuating assembly comprises a main body having protrusion arranged to engage with the trigger mechanism, the main body further comprising a plastics material contact plate, the contact plate comprising a first contact surface at a first orientation, and a second contact surface at a second orientation, the first orientation being different to the second orientation.

The trigger bar may be held at the first end of the arm, and the second end used for manipulating a beam assembly at height within a container. A user of the trigger bar may bring the main body of the trigger bar into contact with the trigger mechanism of a head assembly. The first contact surface of the main body may contact the track. The user may then move the second end of the elongate bar towards the side of the container, such that the main body reacts against the track, and the second contact surface of the main body comes into contact with the track. A pivoting movement moves the protrusion extending from the main body away from the side of the container, such that the trigger mechanism is actuated, and the head assembly becomes free to move along the track. The user may then push or pull the trigger bar to facilitate the movement of the head assembly along the track.

The plastics material contact plate may comprise Acetal. The plastics material contact plate may comprise other plastic material such as polyvinyl chloride (PVC), high density polyethylene (HDPE), polypropylene (PP), etc. The contact plate may be a sleeve configured to surround the main body of the trigger bar.

The main body may be made of metal material, such as stainless steel or aluminium. The track may comprise metal material such as steel or aluminium. The plastics material contact plate may reduce the impact between the main body and the track to reduce the noise created when bringing the main body into contact with the track, and/or through frictional contact when the trigger bar moves along the track.

The protrusion on the main body may comprise a hook portion. In an example, the hook portion may be coupled with a receiver or aperture on the actuator.

The trigger bar may be used to assist the movement of the coupling apparatus along the track. When the trigger mechanism is actuated, the coupling apparatus can move along the track.

The first contact surface of the plastics material contact plate may be configured to contact and move along a track in the first orientation. The second contact surface of the plastics material contact plate may be configured to contact and move along the track in the second orientation.

The first contact surface and second contact surface may meet at a joint or turning point, wherein the trigger bar can move from a first orientation where the first contact surface is in contact with the track, to a second orientation where the second contact surface is in contact with the track. This enables a smooth transition from the first configuration to a second configuration.

The plastics material contact plate may comprise a double-footed profile that guides the plastics material contact plate to move along the track, and allows the user to align the trigger bar accurately with the coupling apparatus. The double-footed profile may improve stability of the trigger bar as the trigger bar is moved along the track.

According to an example, there may be a method of manipulating a trigger mechanism of a coupling apparatus of a decking beam assembly engaged with a track, the method comprising the steps of: a) bringing the first contact surface of a trigger bar according to the fifth aspect of the invention into contact with a track; b) bringing the protrusion into contact with an actuator of the trigger mechanism; and c) applying a force to the first end of the elongated arm such that the second contact surface may come into contact with the track, thus actuating the trigger mechanism to allow movement of the head assembly.

The method may comprise the step of moving the coupling apparatus along the track using the trigger bar.

The method may comprise the step of moving the trigger bar such that the first contact surface comes into contact with the track, thus releasing the force against the actuator of the trigger mechanism and inhibiting movement of the coupling apparatus.

<FIG> show an apparatus <NUM> according to an embodiment of the invention. The apparatus <NUM> is for coupling a beam <NUM>, such as the decking beams described above, to a track along which the apparatus <NUM> can move. For example, the track may be located on an interior wall of a vehicle container oriented to run vertically on the wall and the apparatus <NUM> may be arranged to move vertically along the rail.

The apparatus <NUM> forms part of an assembly (described below with reference to <FIG> and <FIG>) that may be installed into a vehicle to support goods being transported in the vehicle. For example, the vehicle may be a truck or lorry used to transport goods by road. In the example of a lorry, the storage compartment may be fixed to a rearward portion of the lorry's chassis or may be fixed to a trailer that may be connected to a tractor unit. In other examples, the storage compartment may be a container unit (of the type commonly used to transport goods by sea) that can be loaded onto the lorry or lorry trailer. The term container is used herein to refer to any of these possibilities.

The apparatus <NUM> comprises an arm assembly <NUM> and a head assembly <NUM>. <FIG> shows the coupling apparatus <NUM> of <FIG> in an assembled form. In the present embodiment, the beam <NUM> has a rectangular cross section comprising four perpendicular side walls and a hollow centre. The beam <NUM> is configured to receive one end of the arm assembly <NUM> such that the arm assembly slides within the hollow centre of the beam <NUM>.

The arm assembly <NUM> comprises a main body <NUM>. In the present embodiment, the main body has four perpendicular side walls which define a hollow centre and a rectangular cross section. At the furthest most end of the arm assembly <NUM> away from the beam <NUM>, there are two protruding side panels 202a, 202b. The side panels 202a, 202b are connected to the main body <NUM> with mechanical fasteners <NUM>. In the example shown in <FIG>, the side panels 202a, 202b are joined to the main body <NUM> with rivets <NUM>. The rivets <NUM> may be any suitable diameter.

The head assembly <NUM> is joined to the arm assembly <NUM> by a bolt <NUM> and a nut <NUM>. The side panels 202a, 202b, have holes configured to receive the bolt <NUM>. The nut <NUM> and bolt <NUM> may have any suitable diameter and thread that correspond to the diameter of the hole.

The head assembly <NUM> comprises a receiving portion <NUM> which is configured to receive a plastics material <NUM>. In the present embodiment, the head assembly <NUM> has two receiving portions located on opposite sides of the head assembly. Each receiving portion has a circular cross section. The head assembly <NUM> will now be described in more detail with reference to <FIG>.

<FIG> shows a top down view of the head assembly <NUM>. The head assembly <NUM> has a body portion <NUM>. The body portion <NUM> comprises two parallel side walls 116a, 116b similar to the side panels 202a, 202b of the arm assembly <NUM>. The side walls 116a, 116b have holes configured to receive the bolt <NUM> for fastening the head assembly <NUM> with the arm assembly <NUM> as described above.

The side walls 116a, 116b are joined together by a connecting wall <NUM> that is perpendicular to the side walls 116a, 116b, such that it defines a "U-shape" cavity for receiving a trigger mechanism <NUM> therebetween (the trigger mechanism is described in more detail below). At the corner between each side wall 116a, 116b and the connecting wall <NUM>, there is a receiving cavity <NUM> on the external surface of the body portion <NUM> configured to receive a plastics material <NUM>, and an engagement portion 120a, 120b. In the present embodiment, the receiving cavity <NUM> has a semicircular cross section configured to receive a plastics material with a circular cross section, such that a portion of the plastics material remains outside of the receiving cavity <NUM>. In this particular embodiment, the plastics material is a cylindrical rod made of Acetyl material, but other plastic material may be used. In use, the engagement portion 120a, 120b acts as a bearing surface for contact with the track <NUM> (described in more detail below). In use, a portion of the plastics material is in contact with the surface of the track. This reduces the metal-on-metal contact between the head assembly <NUM> and the track <NUM>. Advantageously, the coefficient of friction between the plastics material <NUM> and the metal track <NUM> is lower than that of metal-on-metal, which reduces the noise level when the apparatus <NUM> moves along the track <NUM>.

<FIG> shows a side view of the coupling apparatus when assembled, comprising the beam <NUM>, the arm assembly <NUM>, the head assembly <NUM> as described above. <FIG> also shows a protruding trigger member <NUM> of the trigger mechanism <NUM> (not shown in this figure), which will be described in more detail with reference to <FIG>.

<FIG> shows the apparatus <NUM> when coupled to the track <NUM>. <FIG> shows a top down view of the apparatus <NUM> coupled to the track <NUM>. The engagement portion 120a, 120b acts as bearing surfaces for contact with the track <NUM>. In the present embodiment, the engagement portions 120a, 120b are hooked-shaped such that each engagement portion 120a, 120b, is configured to couple with a groove on the surface of the track <NUM>. A portion of the plastics material <NUM> is received by the receiving cavity <NUM>. A portion of the plastics material <NUM> is in contact with the track <NUM>, which reduces the metal-on-metal contact between the head assembly <NUM> and the track <NUM>.

<FIG> shows a perspective view of the apparatus <NUM> coupled to the track <NUM>. In this embodiment, the engagement portions 120a, 120b are coupled to a groove on the surface of the track <NUM>. The apparatus <NUM> may be held stationary at the position as shown in <FIG> via the trigger mechanism <NUM>. When the trigger mechanism <NUM> is actuated, the apparatus <NUM> may slide along the track <NUM>. The trigger mechanism will be described in more detail below.

<FIG> shows a cross sectional view of the side of an assembly <NUM> comprising the coupling apparatus <NUM> when assembled and connected to a track <NUM>. The beam <NUM>, arm assembly <NUM> and head assembly <NUM>, of the present embodiment have been described above. The features of the trigger mechanism <NUM> will now be described in more detail. The trigger mechanism <NUM> is housed within the main body <NUM> of the head assembly <NUM>. The side walls 116a, 116b and the connecting wall <NUM>, define the housing. The vertical length of each side wall 116a, 116b i.e. along the direction of the track, is longer than the vertical length of the connecting wall <NUM>, so that a gap is formed at the bottom of the connecting wall <NUM> for receiving a rear protruding portion <NUM> of the trigger mechanism <NUM>. The rear protruding portion <NUM> engages with a receiver on the track <NUM>.

The trigger mechanism <NUM> has a main body <NUM> and three protruding portions: an upper hook portion <NUM>, a rear protruding portion <NUM>, and a trigger actuator <NUM>. The upper hook portion <NUM> is linked to a biasing member <NUM>. The biasing member <NUM> is in the form of a tensioned wire or leaf spring. In other embodiments, other biasing members may be used such as a coiled spring. As mentioned above, the rear protruding portion <NUM> engages with receiver on the track <NUM>. The trigger actuator <NUM> protrudes at the bottom of the head assembly <NUM> such that it is in view during normal use.

When the assembly is in use, the biasing member <NUM> urges the trigger mechanism <NUM> such that the rear protrusion <NUM> protrudes from the gap between the side walls 116a, 116b and the bottom of the connecting wall <NUM> to enable engagement with a corresponding receiver in the track <NUM>. In this configuration, the trigger mechanism <NUM> rests against the connecting wall <NUM>. When the trigger actuator <NUM> is pulled away from the wall of the container against the action of the biasing member <NUM>, the rear protrusion <NUM> is retracted into the main body <NUM> of the head assembly <NUM> and out of engagement with the receiver in the track, allowing the head assembly <NUM> to be moved (e.g. slid) along the track.

Within the main body of the trigger mechanism <NUM> is a pivot aperture <NUM>. In use, the trigger actuator <NUM> is used to manipulate the trigger <NUM> about an axis of the pivot aperture <NUM> to move the rear protrusion <NUM> into engagement with a corresponding receiver in the track <NUM> and out of engagement with a corresponding receiver in the track <NUM>.

The trigger actuator <NUM> of this embodiment has a cylindrical shape with an aperture or hole extending into the page according to side view of <FIG>. The trigger actuator <NUM> has a flat flange portion <NUM> such that in use, when the trigger is to be actuated, it may be done by bringing a trigger beam in contact with the flange portion <NUM>, as described in more detail below. The trigger may be actuated using a rod or hook through the aperture.

<FIG> show different perspective views of a trigger bar <NUM> according to a second aspect of the invention. <FIG> show a top view, a side view and a bottom view of a trigger bar, respectively. The trigger bar comprises an elongated arm <NUM>, one end of the elongated arm <NUM> comprising a gripping portion <NUM> for holding in use, and an opposite end comprising a actuating assembly <NUM>. The elongated arm <NUM> and actuating assembly <NUM> may be connected with a nut and bolt (not shown) which pass through a hole at a connecting point <NUM>. It will be appreciated by the skilled person that a suitable nut and bolt could be used to fasten the actuating assembly <NUM> and elongated arm <NUM>.

With reference to <FIG>, the actuating assembly <NUM> will be described in more detail. The actuating assembly <NUM> comprises a main body <NUM> and a protrusion <NUM> extending away from the main body <NUM> in an opposite direction to the elongated arm <NUM>. The actuating assembly <NUM> and protrusion <NUM> are made of the same material such as metal, for example aluminium or stainless steel. The protrusion <NUM> extends outwards and has a perpendicular tab at its furthest end such that it forms an "L-shape". In use, the L-shaped end of the protrusion <NUM> acts as a hook to connect with the flange portion <NUM> of the trigger actuator <NUM> to engage or disengage the coupling apparatus <NUM> with/from the track <NUM>, as shown in <FIG> and described in more detail below.

The main body <NUM> is housed within a plastics material sleeve <NUM>. The sleeve <NUM> has two side portions connected by a base such that the side portions and the base define a slot for the main body <NUM> to be housed. An aperture or hole is located on each side portion which corresponds with the hole at the connecting point <NUM> for receiving a nut and bolt for fastening the plastic sleeve <NUM>, main body <NUM> and the elongated arm <NUM> together.

The external surface of the base of the sleeve <NUM> has a contact plate <NUM> comprising a first contact surface 414a and a second contact surface 414b. The first contact surface 414a and the second contact surface 414b are connected at a joint or turning point such that the first contact surface 414a is at an angle with respect to the second contact surface 414b. In use, the first contact surface 414a may come into contact with the track <NUM> in a first orientation. When the trigger bar is located at or near the coupling apparatus <NUM>, movement of the elongated arm toward the track <NUM> causes the head assembly to rotate around the turning point from the first orientation to a second orientation. The second contact surface 414b is in contact with the track <NUM> in the second orientation. The contact plate <NUM> has an elongated channel <NUM> that runs along the same direction as the axis of the trigger bar and continues from the first contact surface 414a to the second contact surface 414b. The sides of the elongated channel <NUM> define a connecting rail for engaging with the track <NUM>.

In this embodiment, the material of the sleeve is plastic. This is advantageous for reducing the noise levels when the trigger bar <NUM> is coupled to the track <NUM> and when the trigger bar moves along the track to adjust the height of the coupling apparatus, for example. The coefficient of friction between the plastics material and the metal track may be lower than metal-on-metal, and thus the former will be quieter than the latter. Additionally or alternatively, impacts between the plastics material and the track may be partially absorbed by the plastics material, thereby potentially reducing noise compared to metal on metal impacts.

<FIG> shows an example of a track <NUM> that may be installed on an interior wall of a container. The track <NUM> may include fixing apertures or holes through which fixings (e.g. screws) may pass to fix the track <NUM> to the interior of the container. Receivers <NUM> spaced apart along the track <NUM> are provided to receive a protrusion <NUM> of the trigger mechanism <NUM> described above with reference to <FIG>, thereby preventing movement of the apparatus along the track <NUM>.

<FIG> shows a cross sectional side view of a decking beam assembly comprising the coupling apparatus <NUM> and trigger bar <NUM> as described above. In an embodiment, the contact plate <NUM> of the plastic sleeve <NUM> is connected to the track <NUM> such that it can move (e.g. slide) along the track <NUM>. Within the head assembly <NUM> of the coupling apparatus <NUM>, the trigger mechanism <NUM> is resting against the connecting wall <NUM> of the head assembly <NUM>. When the trigger actuator <NUM> is pulled inwardly against the action of the biasing member <NUM> using the L-shaped protruding end <NUM> of the trigger bar, the rear protrusion <NUM> of the trigger mechanism is retracted into the main body <NUM> of the head assembly <NUM> and out of engagement with the receiver in the track <NUM>, allowing the head assembly <NUM> to be moved (e.g. slid) along the track. The trigger bar <NUM> and coupling apparatus <NUM> may slide along the track together when adjusting the height of the beam <NUM>. When the coupling apparatus is moved, a portion of the plastics material <NUM> (not shown in <FIG>) of the head assembly <NUM> remains in contact with the track <NUM>. In this configuration, the noise level may be reduced due to the lower coefficient of friction between the plastics material and the metal track compared to the coefficient of friction between metal connected to metal.

In some embodiments, the coupling apparatus <NUM> may comprise an arm assembly <NUM> configured to receive a beam <NUM>. In such an embodiment, the dimensions of the arm assembly <NUM> may be larger than the dimensions of the beam <NUM>. The arm assembly <NUM> may slidably receive the beam <NUM> such that the beam is within the cavity defined by the side walls of the arm assembly.

In some embodiments, the plastics material <NUM> may be made of other material that provides a low coefficient of friction when in contact with a metal track, and/or absorbs impacts between the head assembly and the metal track. As described above, the head assembly <NUM> comprises two receiving portions <NUM>, each configured to receive a plastics material. In some embodiments, there may be a single receiving portion <NUM> and a single plastics material <NUM>. In other embodiments, there may be more than two receiving portions <NUM>, each configured to receive a plastics material <NUM>.

In some embodiments, the receiving portion <NUM> may be a groove. In other embodiments, the receiving portion <NUM> may be configured as a spheroid joint, for receiving a spherical shaped plastics material <NUM>, for example in a ball-and-socket joint configuration. The cross sectional shape of the receiving portion <NUM> may be the same or similar to the cross sectional shape of the plastics material <NUM>, and vice versa, so that the plastics material <NUM> fits snuggly within the receiving portion <NUM>. In other embodiments, the receiving portion <NUM> may have a different cross sectional shape to the plastics material <NUM>.

The plastics material <NUM> may be a rod. The plastics material may be a hollow rod. The plastics material may have a different shape, such as rectangular rod. In some embodiments, the plastics material may be a spherical ball, for example. The plastics material may be a hollow rod or plastic tube comprising a metal core. This may advantageously provide stability and structure to the profile of the plastic material.

The plastics material <NUM> may comprise of a combination of different materials. The plastics material <NUM> may comprise other material that has a low coefficient of friction such that when the plastics material is in contact with a metal track, the head assembly <NUM> can move (e.g. slide) along the track, and the noise created by the frictional contact is reduced. The portion of the plastics material that protrudes away from the receiving cavity <NUM> may be between <NUM>% to <NUM>% of the plastics material.

The sleeve <NUM> of the trigger head may comprise a combination of plastic materials that have a low coefficient of friction when coupled with a metal track. The external surface of the base of the sleeve <NUM> may be coupled to the track using a double-footed profile. The double-footed profile of the sleeve <NUM> assists the sleeve <NUM> to couple and move along with the track. The double-footed profile allows the user to align the trigger bar <NUM> with the coupling apparatus <NUM>. The double-footed profile assists with coupling the trigger bar with the track for stability and guidance.

The track <NUM> may comprise a plastics material arranged on a surface of the track <NUM> such that the plastics material provides a contact surface between the coupling apparatus <NUM> and the metal track <NUM> when the coupling apparatus <NUM> is engaged with the track <NUM>. The plastics material may be a rod of plastics material arranged to fit within a receiving portion or groove running along the length of the track <NUM>. The plastics material may be a sheet of plastics material covering the surface of the track <NUM>. For example, the sheet of plastics material may be moulded to fit around the receivers <NUM> and other indentations on the surface of the track <NUM>.

The coupling assembly of <FIG> may be used with a traditional trigger bar as known by the person skilled in the art, which comprises an elongated arm with a bent or doglegged portion at one end, which acts as a trigger head for actuating the trigger actuator <NUM> of the trigger mechanism <NUM>.

Claim 1:
An apparatus (<NUM>) for coupling a beam (<NUM>) to a track (<NUM>) comprising:
an arm assembly (<NUM>) having a first end arranged to interface with the beam (<NUM>), and a second end opposite the first end,
a head assembly (<NUM>) coupled to the second end of the arm (<NUM>) and
arranged to engage with the track (<NUM>) to inhibit movement of the head assembly (<NUM>) along the track (<NUM>), wherein the head assembly (<NUM>) comprises a receiving portion (<NUM>) and a plastics material (<NUM>) received within the receiving portion (<NUM>), characterised in that the receiving portion (<NUM>) is a groove and the plastics material (<NUM>) is a rod having a circular cross-section, such that the plastics material (<NUM>) provides a contact surface between the head assembly (<NUM>) and the track (<NUM>) when the head assembly (<NUM>) is engaged with the track (<NUM>).