WO2020254789A1

WO2020254789A1 - Improvements in or relating to rail trolleys

Info

Publication number: WO2020254789A1
Application number: PCT/GB2020/051446
Authority: WO
Inventors: David Thomson
Original assignee: Thomson Engineering Design Ltd
Priority date: 2019-06-18
Filing date: 2020-06-16
Publication date: 2020-12-24
Also published as: GB201908742D0; GB2584884A; GB201908792D0

Abstract

An improved rail trolley apparatus is provided having an improved braking system, improved wheel construction, and/or the provision of an extender which allows for the rail trolley (10) to be used with a third rail outside of a standard rail track (12).

Description

Improvements in or Relating to Rail Trolleys

The present invention relates to a rail-trolley rail wheel, particularly but not necessarily exclusively for movably supporting a rail trolley on a rail. The invention further relates to a rail-trolley fail-safe brake assembly, and further to a rail trolley for moving railway components on a railway track. A rail trolley system for moving railway components on a railway track is also disclosed.

Rail trolleys are devices which run on railways and are typically manually pushed by labourers. They are utilised to carry objects along the railway track, most commonly, rails themselves for installation and/or maintenance purposes.

Rail trolleys typically comprise a cross-member which spans the width of a railway track, supported by a pair of wheel assemblies engagable with the rails on either side of the track. The cross-member can then be used to support the weight of rails, usually via a clamping head depending therefrom.

Rail trolleys tend to have fail-safe brakes to ensure that they are only moved when intended. These fail-safe brakes are attached to one of the wheel assemblies, with the wheels on that side of the trolley being in a braking condition by default. To move the rail trolley, the operator activates a lever at or adjacent to the wheel assembly having the brake to release the braking force, allowing the rail trolley to be pushed. This arrangement causes many issues.

Firstly, such rail trolleys, in order to minimise weight, utilise cast aluminium wheels. The small contact area between the wheels and the rails results in very high stress within the material. The high stress causes the aluminium to spall, which is a pulverising of the work-hardened outer layer, and therefore replacement of the wheels is required on a regular basis, resulting in down time for the rail trolley.

Secondly, the positioning of the brake lever at one side of the trolley requires a user to hand operate the lever during movement of the trolley. This forces the operator to push the trolley from the side, slewing the trolley, and thereby increasing friction between the wheels and the rail making it harder to push. It also necessitates the operator walking in close proximity to the rails and the clips which fasten the rails to the sleepers, increasing the risk of accidental injury.

Furthermore, since the rail trolley in the art only has brakes on two of its wheels, there is an increased risk of runaway, particularly when the trolley is heavily laden and/or positioned on an incline. Again, there is a risk of injury to operators in this case. Since the rail trolley is physically located on the rails, it is also difficult to perform maintenance on the rails themselves and on third rails which are offset with respect to the main railway track, meaning that the trolley has to be derailed, making repair jobs more complicated.

The present invention seeks to provide a solution to these problems.

According to a first aspect of the present invention, there is provided a rail-trolley rail wheel for movably supporting a rail trolley on a rail, the rail wheel comprising: an outer wheel body portion having a circumferentially extending tread wall for defining a tread of the rail wheel; and an inner wheel body portion which is at least in part receivable inside the outer wheel body portion, the inner wheel body portion including a radial support wall which buttresses at least part of the tread wall of the outer wheel body.

The provision of an improved rail wheel increases the strength of the rail wheel at or adjacent to the point of contact of the rail wheel with the rail to be traversed. The present design also reduces the weight of the wheel without compromising on the structural integrity thereof. As such, a strong and stable wheel can be produced which is much less susceptible to warping, spalling or cracking under high stress. The radial support wall increases the effective thickness of the wheel section over the area of the wheel most commonly running on the rail.

Optionally, at least one of the outer and inner wheel body portions may be formed from iron, steel, or an alloy thereof.

Since the construction of the wheel is such that the point of contact of the wheel with the rail can be reinforced, and by extension, the weight elsewhere reduced, more robust materials than aluminium can be utilised in the construction of the wheel without incurring a weight penalty.

Preferably, the outer and inner wheel body portions may comprise spun steel.

Spun steel can be used to create complex wheel geometries with little welding requirements which might otherwise introduce weaknesses into the wheel. Furthermore, the use of spun steel sections allows the diameter of the wheel to be comparatively large when compared with aluminium wheels known in the art, which in turn makes the rail trolley easier to push along the track.

The tread wall and/or radial support wall may be formed from sheet material.

A sheet material helps to keep the weight of the rail wheel to a minimum, without producing any significant deleterious effect to the quality of the rail wheel. Optionally, the outer and inner wheel body portions may contiguously meet to form a flange of the rail wheel.

Since the flange of the rail wheel is primarily for locating the wheel in the correct position on the rail, rather than providing load-bearing capacity, it is preferred that the inner and outer wheel body portions be engaged with one another at the flange, thereby resulting in a wheel which has reduced rates of failure.

Preferably, the radial support wall may form a brake drum for the rail wheel.

Since the rail wheel can be formed from relatively small amounts of material, it becomes possible to factor a brake drum into the design of the rail wheel, which increases the options for braking assemblies which may reduce the risk of runaway of the rail trolley even in a braking condition. An internal brake drum is less affected by contamination or wear of the wheel tread surface. Contaminants to the rail wheel surface can be transferred, for example, by the leaves on the line’ effect, which adversely affects the friction coefficient between both the wheel and brake and the wheel and rail. The present arrangement shows improved wet-weather performance as a result.

A bearing receiver may extend axially through the tread wall and/or radial support wall.

The provision of a bearing receiver allows for the simple wheel design to be quickly replaced by removal from an axle in the event of a fault developing.

Preferably, the radial support wall may abut the bearing receiver.

The bearing receiver may also serve to buttress the radial support wall, reducing the risk of internal buckling thereof. This potentially mitigates some of the risk associated with using a sheet material.

Optionally, the inner wheel body portion may comprise a cylindrical wall connected to the radial support wall which is in contact with at least part of the tread wall.

The internal cylindrical wall may not only provide the ability to construct a brake drum, but may also act to improve the buttressing effect provided by the radial support wall. This results in an at least in part double-walled wheel construction.

According to a second aspect of the invention, there is provided a rail-trolley fail-safe brake assembly comprising: a rail wheel having a brake drum; a brake shoe receivable in the brake drum for applying a braking force the rail wheel; a brake-engagement member to which the brake shoe is mounted, the brake-engagement member being pivotable between a braking condition and a release condition of the brake shoe with respect to the brake drum, the brake-engagement member having a cantilevered indicator arm; and a biasing element for biasing the brake shoe towards the brake drum, a biased position of the cantilevered indicator arm being indicative of a wear on the brake shoe.

In order to mitigate the effects of uneven wear on brake shoes of a rail wheel, it is desirable to provide an indicator which shows the wear in a visual manner to the user. In the present arrangement, the positioning of a, preferably cantilevered, indicator arm, which is coupled to the brake shoe, can be used as such a visual indicator for the user.

The rail-trolley fail-safe brake assembly may further comprise an actuation assembly which is engagable with the brake-engagement member for activating the release condition of the brake shoe.

It is preferred that an actuation assembly, configured to permit remote activation of the brake shoe by a user, be provided, so that the user does not need to activate the brakes in a dangerous manner at or adjacent to the rail wheels.

Optionally, the actuation assembly may be engagable with the cantilevered indicator arm.

Advantageously, the indicator arm also may form part of the activation mechanism for the brake shoe, which reduces the need for additional component parts to be provided.

In a preferable embodiment, there may be provided two said rail wheels, brake shoes, brake- engagement members and biasing elements are provided, the actuation assembly being engagable with both of the cantilevered indicator arms.

An improved braking arrangement can be provided which is operable via a single actuation assembly, which brakes more than one wheel simultaneously. This reduces the risk of runaway of the rail trolley.

The cantilevered indicator arms may be aligned to one another, a relative displacement of the cantilevered indicator arms being indicative of a relative wear between the two brake shoes.

Since the actuation assembly engages with both brake shoes simultaneously, any uneven wear may be visible at the point of engagement with the actuation assembly. This will manifest as misalignment of the cantilevered engagement arms in the braking condition, which can be used as a relative indicator of wear between the brake shoes.

Optionally, the brake assembly may further comprise a rail hook which is coupled to the actuation assembly and which is movable between an engaged condition in the braking condition of the brake shoe and a disengaged condition in the release condition of the brake shoe. The rail hook prevents the wheels sliding towards the centre of the track and drooping from the rail whilst the trolley is supported by the jack at the other end. The combination of the wheel flanges being on the inside of the rail and the rail hook on the outside combine to limit lateral movement of the assembly. This is important because the wheels are tapered hence the weight on the wheels supporting one end of the trolley produces a lateral force due to the wheel taper angle. In normal use, this is balanced by the lateral force arising from the wheels on the opposite side or resisted by their flanges if the loads are unbalanced. However, when the other side is supported by the jack, this is most likely to be resting on the railway ballast and rolling of the stones underneath may allow lateral movement to occur. The rail hooks are designed to guard against this potential issue. It is advantageous that the operation of such a rail hook be linked to the operation of the brake assembly.

Preferably, the or each rail wheel may be formed from spun steel.

According to a third aspect of the invention, there is provided a rail trolley comprising a chassis and at least one rail-trolley fail-safe brake assembly in accordance with the second aspect of the invention, wherein the chassis includes an indicator port at or adjacent to the or each cantilevered indicator arm to permit visual inspection thereof.

The chassis of the rail trolley is provided such that the positions of the or each cantilevered engagement arm can be readily seen by a user, providing the visual indication of wear in a simple manner.

According to a fourth aspect of the invention, there is provided a rail trolley for moving railway components on a railway track, the rail trolley comprising: a left-hand wheel assembly having first and second rail wheels for engagement with a left-hand rail of the railway track and including a left-hand brake assembly for releasably braking the first and second wheels; a right-hand wheel assembly having third and fourth wheels for engagement with a right-hand rail of the railway track and including a right-hand brake assembly for releasably braking the third and fourth wheels; a cross-member which extends between the left-hand and right-hand wheel assemblies; a brake control member positioned on the cross-member configured to operate the left-hand and right- hand brake assemblies simultaneously.

Braking assemblies to date have been provided on a single side of a rail trolley, necessitating the operator standing close to the side of the braking assembly and thus pushing only from one side, which results in the user slewing the trolley as it moves, increasing wear on the rail wheels. In the present invention, the user can disengage all four brakes from the centre of the rail trolley, reducing the risk of both slewing and runaway of the vehicle.

Optionally, the brake control member may extend across the full extent of the cross-member. The utility of the brake control member may be increased if it is elongate, as this allows the brake to be disengaged from several different positions along the length of the cross-member. This for example allows multiple users to push the rail trolley, and/or may allow a single user to change position to avoid obstacles without re-engaging the brakes.

Preferably, the brake control member may be a movable bar.

A movable bar provides a natural fit for a push trolley, since the movable bar can be pushed in the same direction in which the rail trolley is to be pushed, simplifying the process for brake disengagement.

In one embodiment, the first, second, third and fourth wheels may be formed from spun steel.

Optionally, the left- and/or right-hand brake assemblies may be rail-trolley fail-safe brake assemblies, preferably in accordance with the second aspect of the invention.

According to a fifth aspect of the invention, there is provided a rail trolley system for moving railway components on a railway track, the rail trolley comprising: a left-hand wheel assembly having first and second rail wheels for engagement with a left-hand rail of the railway track; a right-hand wheel assembly having third and fourth rail wheels for engagement with a right-hand rail of the railway track; a cross-member which extends between the left-hand and right-hand wheel assemblies and having an engagement connector which extends outwardly past at least one of the left-hand and right-hand wheel assemblies; and a trolley support stand assembly which is demountably engagable with the engagement connector of the cross-member to permit the rail trolley to be supported on the ground.

At present, rail trolleys are limited by their movability along a rail track, and cannot extend laterally thereof. This causes problems for maintenance at, for instance, junctions. The present invention solves this problem by providing a means for extending the length of the cross-member by the use of a trolley support stand assembly, allowing the rail engagement head to operate beyond the constraints of the wheel assemblies.

Optionally, the trolley support stand assembly may comprise a trolley support stand and a cross member extender, the cross-member extender being engagable with the engagement connector and the trolley support stand to extend the length of the cross-member.

Optionally the use of the trolley support stand and the cross member extender may allow for the wheel assembly at that end of the trolley to be removed to produce the form of a gantry extending over the running and third rail locations allowing materials to be collected and delivered to the sleeper ends or beyond. The invention will now be more particularly described, by way of example only, with reference to the accompanying drawings, in which:

Figure 1 shows a front perspective representation of one embodiment of a rail trolley in accordance with the third aspect of the invention;

Figure 2 shows a rear perspective representation of the rail trolley of Figure 1 ;

Figure 3 shows a perspective representation of an in-use condition of two rail trolleys as shown in Figure 1 , carrying two railway rails;

Figure 4 shows an exploded perspective representation of the rail trolley of Figure 1 ;

Figure 5a shows a front view of a rail wheel of the rail trolley of Figure 1 , in accordance with the first aspect of the invention;

Figure 5b shows a vertical cross-section through the rail wheel shown in Figure 5a;

Figure 6 shows a rear perspective representation of the rail trolley of Figure 1 , inclusive of some additional optional components;

Figure 7 shows an exploded perspective representation of the rail trolley of Figure 6;

Figure 8 shows a perspective representation of the cross-member of the rail trolley of Figure 1 ;

Figure 9 shows a perspective representation of the rail-trolley fail-safe brake assembly of the rail trolley of Figure 1 , in accordance with the second aspect of the invention, with the chassis omitted for clarity, the rail-trolley fail-safe brake assembly being shown in a braking condition;

Figure 10 shows an external perspective representation of the rail-trolley fail-safe brake assembly of Figure 9, inclusive of the chassis;

Figure 11 shows the external perspective representation of the rail-trolley fail-safe brake assembly of Figure 10, with the chassis overlain;

Figure 12 shows a perspective representation of the rail-trolley fail-safe brake assembly of Figure 9, the rail-trolley fail-safe brake assembly being shown in a release condition;

Figure 13 shows an external perspective representation of the rail-trolley fail-safe brake assembly of Figure 12, inclusive of the chassis; Figure 14 shows an internal perspective representation of the rail-trolley fail-safe brake assembly of Figure 12, inclusive of the chassis;

Figure 15 shows a top perspective representation of the chassis of the rail-trolley fail-safe brake assembly of Figure 10, indicating the cross-member support portion;

Figure 16a shows a left perspective representation of a cross-member extender of the rail trolley of Figure 1 ;

Figure 16b shows a right perspective representation of the cross-member extender of Figure 16a;

Figure 17 shows a side perspective representation of the rail engagement head of the rail trolley of Figure 1 ;

Figure 18a shows a side perspective representation of the rail engagement jaws of the rail engagement head of Figure 17;

Figure 18b shows a front perspective representation of the rail engagement jaws of Figure

18a;

Figure 19 shows a perspective representation of the trolley support stand of the rail trolley of Figure 6;

Figure 20 shows a side representation of the trolley support stand of Figure 19, with the inset showing a vertical cross-section therethrough;

Figure 21 shows an in-use perspective representation of two rail trolleys as shown in Figure 1 ;

Figure 24 shows a perspective representation of the use of the cross-member extender of Figures 16a and 16b being engaged with the cross-member of one rail trolley of Figure 21 ;

Figure 23 shows a perspective representation of the cross-member extender of Figure 24 in a part-assembled state;

Figure 24 shows a perspective representation of the cross-member extender of Figure 23 in an engaged state;

Figure 25 shows a perspective representation of the rail trolley of Figure 24 inclusive of a trolley support stand connected to the cross-member extender; and Figure 26 shows a perspective representation of the rail trolley of Figure 25, with the wheel assembly removed.

With reference to Figures 1 and 2, there is shown a rail trolley, indicated globally at 10, for moving railway components on a railway track 12, as is shown in Figure 3.

The rail trolley 10 comprises left- and right-hand wheel assemblies 14a, 14b which are spaced apart from one another so as to be receivable upon a railway track 12. The left- and right-hand wheel assemblies 14a, 14b are interconnected by a cross-member 16 which supports a rail engagement head 18 for engagement with a rail 20.

A handle module 22 is provided, which includes a user engagement handle 24 is provided via which a standing user can grip and push the rail trolley 10. The user engagement handle 24 includes a movable bar 26, forming a brake control member, which is connected to braking assemblies of the left- and right-hand wheel assemblies 14a, 14b to effect braking and/or release of a braking force.

In trials, it was found that, when pushing a trolley up hill, operators were unable to bring themselves to release the moveable bar 26, due to the fear that the rail trolley 10 would roll back onto them. The user engagement handle 24 is, in a preferable embodiment, reversible so that the operator can choose to pull push the moveable bar 26 away from himself or pull it towards himself, in the manner of an airport baggage trolley, and the latter has proven the most successful and popular option.

Each wheel assembly 14a, 14b preferably comprises a chassis 28 and two wheels 30, and it is preferred that a braking force can be applied to each of the wheels 30. The chassis 28 is preferably formed as an inverted T-shaped chassis, which is at least in part hollow to allow connectors for the braking assemblies to pass therethrough.

The rail engagement head 18 comprises a set of rail engagement jaws which are engagable with an upper portion of a rail 20 to be moved. Additional rail engagement elements, such as the rail support hook 32 or carrier shown in Figure 3 supporting an underside of the rail 20, may be provided to allow the rail trolley 10 to support more than one rail 20 simultaneously. Other, more specialised, rail carriers could also be provided.

In use, rail trolleys 10 will typically be used in pairs, with the rail engagement heads 18 and/or rail engagement elements such as the rail support hook 32 engaging with the rails 20 at or adjacent to opposite ends of the rail 20. This allows the rails 20 to be moved along the railway track 12. The assembly of the rail trolley 10 is shown in Figure 4. Each of the chassis 28 of the wheel assemblies 14a, 14b includes a support connector 34, preferably a slot connector, which is engagable with the cross-member 16. Preferably, this is constructed in such a way that the ends of the cross-member 16 extend outwardly or are directed outwardly of the support connector 34 such that elements can be engaged with the end of the cross-member 16 without interference from the wheel assemblies 14a, 14b.

The user engagement handle 24 may be provided as a modular unit with the movable bar 26, which is directly engagable with upstanding struts 36 of the wheel assemblies 14a, 14b. This allows there to be coupling engagement between the braking assemblies and the movable bar 26.

The rail engagement head 18 is receivable over the cross-member 16. The rail engagement head 18 may preferably engage with the cross-member 16 via a rack-and-pinion engagement; here the rack 38 can be seen on the top of the cross-member 16, extending across its entire length. A manual crank 40 on the rail engagement head 18 may provide a simple means of moving the rail engagement head 18 back and forth across the rail trolley 10. A brake may also be provided to lock the position of the rail engagement head 18 on the cross-member 16.

The structure of the wheels 30 can be seen in detail in Figures 5a and 5b. Each wheel 30 has a cylindrical or slightly frusto-conical rail-engagement surface formed by a tread wall 42 which provides the point or surface of contact between the wheel 30 and the rail 20. The wheel 30 also includes a flange 44 as required for rail movement.

As is shown in Figure 5b, the wheel 30 has a specific structure designed to improve the strength of the wheel 30 without significantly increasing the weight. This allows the wheel 30 to be formed from iron, steel, or an alloy thereof, particularly from spun steel. The overall outer cross-section of the rail wheel 30 is defined in railway standards, as well as the minimum overall width of the wheel 30. The diameter of the wheel 30 at the point of contact with the rail 20 is also defined in railway standards in accordance with the weight to be borne. The rail wheel 30 may include a tyre, for example, made from plastics material, which may offer quieter operation and electrically insulate the trolley to prevent it from tripping track circuits. The plastic-tyred variant may, however, be heavier. Alternatively, insulating sleeves could be provided around the inner and/or outer faces of the wheel bearings, and additional conductive paths can be avoided by the use of an insulating brake lining material.

The wheel 30 includes an outer wheel body portion 46 having the circumferentially extending tread wall 42 for defining a tread of the wheel 30, and an inner wheel body portion 48 which is at least in part receivable inside the outer wheel body portion 46. The inner wheel body portion 48 includes a radial support wall 50 which buttresses at least part of the tread wall 42 of the outer wheel body 46. The radial support wall 50 is preferably positioned around half-way along the tread wall 42, such that it aligns, in-use with or substantially with the centre of the rail 20.

The inner wheel body portion 48 may also include a cylindrical or slightly frusto-conical wall 52 connected to the radial support wall 50 and which is in contact with at least part of the tread wall 42. This may lead to a double-thickness wall section at the point of contact of the tread wall 42 with the rail 20.

A bearing receiver 54 or hub is provided which extends axially through the tread wall 42 and/or radial support wall 50 and which is dimensioned to support a bearing of the left-hand or right- hand wheel assembly 14a, 14b. The radial support wall 50 may abut the bearing receiver 54 in order to provide further structural rigidity.

The inner wheel body portion 48 therefore forms a cavity 56, and this cavity 56 is capable of acting as a brake drum, as will be described in more detail hereafter.

The bearing receiver 54 is preferably formed from turned steel, and is designed to incorporate ball bearings for supporting on an axle. In a preferred design the bearing receiver 54 may be welded to the outer wheel body 46, formed from spun steel in the preferred embodiment. The inner wheel body 48, also preferably formed from spun steel, may then meet the outer wheel body 46 at the top of the flange 44 where they are preferably welded together. This forms a robust rail wheel 30, which will not buckle easily, and will require significantly less maintenance than an equivalent aluminium wheel as used in the art. Optionally the bearing receiver 54 will include a machined flange to abut a radial wall of the inner or outer wheel bodies 46, 48 to assist in aligning the bearing receiver 54 in an axial direction.

The optional configurations of the rail trolley 10 can be seen in Figures 6 and 7.

The rail support hook 32 is provided so as to be releasably engagable with one or more locators 58 on the cross-member 16, and will be held in position by the weight of the rail 20 being supported. In a preferred embodiment, two locators 58 and corresponding rail support hooks 32 may be provided, allowing two lengths of rail to be carried.

The chassis 28 of one or more wheel assemblies, here the right-hand wheel assembly 14b, may incorporate one or more holders 60 or supports for optional equipment. In the depicted embodiment, said holders 60 are mounted to a wheel bracket 62 of the chassis 28. The optional components illustrated are a cross-member extender 64 and a trolley support stand 66, which can be used to respectively extend the length of the cross-member 16 and then allow the rail trolley 10 to be supported on the ground on one side thereof. This allows for the rail trolley 10 to provide access to a third rail, for example, which is positioned outwardly of the usual railway track 12. It will be appreciated that the cross-member extender 64 and trolley support stand 66 could be integrally formed with one another as a single modular unit.

The partially free-standing condition is illustrated in Figure 7. It is noted that in order to correctly configure the rail trolley 10 in this regard, the user engagement handle 24 unit and right-hand side wheel assembly 14b may need to be removed, so as to avoid collisions with the engagement head 18.

The cross-member 16 can be visualised in more detail in Figure 8. As illustrated, the cross member 16 is formed having a largely hollow elongate body 68, with the rack 38 of the rack-and- pinion mechanism extending preferably along the entire longitudinal extent of the top surface thereof. A handle 70 may also be provided, which allows for ready assembly and disassembly of the modular rail trolley 10. In the present embodiment, the whole rail trolley 10 is modularly disassemblable into components of no more than 22kg, which can permit one-handed lift of each part.

The locators 58 for engaging with the rail support hook 32 may be provided symmetrically, to allow the rail support hook 32 to be used on either side of the centre of the cross-member 16, and it will be appreciated that any number of appropriate said locators 58 may be provided. Here, the locators 58 are formed as bosses on the surface of the cross-member body 68.

At least one end of the cross-member 16 may be provided with an interface connector 72 which is dimensioned to engage with the cross-member extender 64, as will be discussed in more detail in due course. The interface connector 72 is here formed as a connector plate covering part of an opening of the end of the cross-member 16 against which the cross-member extender 64 may hook. There may also be internal engagement members, such as rods or stops which may assist with the hooking of the cross-member extender 64 into position.

The cross-member 16 may also include a plurality of seating engagement members, such as the seating pins 74 illustrated, which are suitable for engaging with corresponding locators on the support connectors 34 of the left-hand and right-hand wheel assemblies 14a, 14b.

A braking assembly 76 of the wheel assembly 14a is shown in Figure 9. The braking mechanism 76 comprises a rail wheel 30 having a brake drum 78 formed by the inner wheel body 48, though it will be appreciated that the braking assembly 76 could be provided with existing rail wheels.

A brake shoe 80, brake pad, or similar brake element is provided which is receivable in the brake drum 78, for applying a braking force the rail wheel 30. The brake shoe 80 is mounted to a brake- engagement member 82, and is here formed as a pivotable lever, with the brake shoe 80 being connected at one end, the pivot being coaxial with the axle of the rail wheel 30. The brake- engagement member 82 is therefore pivotable between a braking condition and a release condition of the brake shoe 80 with respect to the brake drum 78.

On the opposite side of the pivot, the brake-engagement member 82 has a cantilevered indicator arm 84, which not only acts to allow the brake shoe 80 to be released, but also can act as an indicator of brake shoe 80 wear. A biasing element 86, such as the depicted spring, for biasing the brake shoe 80 towards the brake drum 78 is also provided, where a biased position of the cantilevered indicator arm 84 then becomes indicative of a wear on the brake shoe 80; as the brake shoe 80 wears, the distal tip of the cantilevered indicator arm 84 will have a different rest position to that of an unworn brake shoe 80.

Two said cantilevered indicator arms 84 can be provided in opposition to one another, for two rail wheels 30 on the same wheel assembly 14a. The cantilevered indicator arms 84 also then provide an indication of relative wear for the brake shoes 80 on the two rail wheels 30, since the distal tips of the cantilevered indicator arms 84 will become misaligned to one another.

An actuation assembly 88, here indicated as a preferably pneumatic or hydraulic jack, is provided which can couple to the movable bar 26 of the user engagement handle 24 so that the braking assembly 76 can be activated therefrom. The actuation assembly 88 may also be coupled to a rail hook 90 which serves to limit lateral motion of the rail trolley 10 in the braking condition. The actuation assembly 88 there therefore urge the rail hook 90 out of connection with the rail 20 when in the release condition of the brake shoes 80.

The actuation assembly 88 here comprises a plunger head 92 which is acted upon by the brake control member to push down rod 94. This in turn pivots lever 96 around a fulcrum pin 98 causing pull rod 100 to rise. In a preferred design, the mass moment of the pull rod 100 about the lever 96 exceeds the mass moment of the plunger head 92 and push rod 62 so that when the movable bar 26 is released, the mechanism returns to a rest condition. Other braking-force transmission means could, however, be considered, such as a hydraulic or pneumatic transmission.

Figures 10 and 1 1 show the wheel assembly 14a in the braking condition. When the movable bar 26 is not activated, the biasing elements 86 urge the brake shoes 80 against the brake drum 78, and the actuation assembly 88 returns to a rest condition, preferably under hydraulic or pneumatic pressure. A jack head 102 or similar flange part of the actuation assembly 88 is then no longer in contact with the cantilevered indicator arms 84, and a hook support 104 in connection with the rail hook 90 remains in a lowered and engaged condition with the rail 20. Upwards travel of the rail hook 90 may be limited by a biasing element, such as a spring. The braking assembly 76 can be seen in the release condition in Figure 12, with the corresponding image of the wheel assembly 14a being shown in Figure 13. The actuation assembly 88 has been activated, drawing up the jack head 102, and raising the cantilevered indicator arms 84. The pivoting of the cantilevered indicator arms 84 counteracts the force of the biasing element 86, and the brake shoes 80 are drawn out of contact with the brake drum 78. The hook support 104 is also simultaneously raised, lifting the rail hook 90 into a disengaged condition with the rail 20. The rail hooks 90 must be raised in order to avoid collisions with elements of the rail track 12, and therefore the integration of the actuation assembly 88 with the operation of the rail hooks 90 is a significant advantage.

Figure 14 shows the wheel assembly 14a from the reverse side to that of Figure 13, and illustrates the indicator port 106 of the chassis 28 which allows the user to visually inspect the position and/or relative alignment of the distal ends of the cantilevered indicator arms 84. The indicator port 106 may be provided with one or more indicia which illustrates to the user the expected positions of the cantilevered indicator arms 84, thereby providing a visual indication of wear.

The connection means between the wheel assembly 14a and the cross-member 16 can also be seen in Figure 14. An upper end of a preferably threaded shaft 108 may be provided which aligns with a hole in the base of the cross-member 16. Activating the threaded shaft 108, for example, by turning the rotatable bar 1 10 may then drive the ned of the threaded shaft 108 into the base of the cross-member 16, locking it in place.

The threaded shaft 108 may also include a flange 1 12 which presses against the base of the cross-member 16, which may urge the seating pins 74 into contact with the locators 1 14 of the support connector 34. By adjustment of the seating pins 74, preferably formed as grub screws, an angle between the upright section of the wheel assembly 14a and the cross-member 16 can be adjusted, which may allow for some modification of the width of the rail trolley 10.

The upper portions of the chassis 28 of the wheel assembly 14a can be seen in detail in Figure 15. In particular, the support connector 34 for engagement with the cross-member 16 is visible, as are the locators 1 14 for receiving the seating pins 74 thereof for quick engagement of the cross-member 16 to the wheel assembly 14a. This greatly simplifies the process for modularly assembling and disassembling the rail trolley 10.

The cross-member extender 64 can be seen in more detail in Figures 16a and 16b, and has a cross-sectional shape which matches that of the cross-member 16. The upper surface also includes an extender rack 1 16 which, once engaged, abuts the rack 38 of the cross-member 16. The cross-member extender 64 includes an engagement element, here formed as a hook portion 1 18 which is receivable by, and preferably into, the cross-member 16 to effect a connection therebetween. A locator nub 120 is provided on the cross-member extender 64 to locate into the interface connector 72.

The cross-member extender 64 may also include an interface connector 122 which matches the interface connector 72 of the cross-member 16, so as to allow daisy-chaining of a plurality of cross-member extenders 64 if required.

A more detailed view of the rail engagement head 18 is shown in Figure 17. The rail engagement head 18 includes an upper body portion 124 which is receivable over the rack 38, and has a pinion gear which is operable via the manual crank 40 to permit lateral motion along the cross member 16. This, of course, could be motorised as required.

The upper body portion 124 preferably includes at least one roller 126 which may be grooved to allows them to pass over the rack 38 attached to the cross-member 16 and/or cross-member extender 64 without impediment. A carry handle 128 may also be provided for ease of engaging and disengaging of the rail engagement head 18.

A lower body portion 130 is also provided which supports the rail engagement jaws 132. A raising and lowering mechanism is provided to move the rail engagement jaws 132 between a raised condition which is close to the cross-member 16, and a lowered condition which is in-use positionable at or adjacent to a rail 20 to be lifted, and this is spaced away from the rail engagement jaws 132. Here, the raising and lowering mechanism comprises a pully 134 operated by a rotatable wheel 136. There are no ratchets or trips to operate, and the rotatable wheel 136 allows for vertical movement of the rail engagement jaws 132. An automatic fail-safe brake may be provided to prevent a drop under gravity.

The rail engagement jaws 132 can be seen in more detail in Figures 18a and 18b, and comprise first and second jaw members 138a, 138b which are pivotably engaged with one another via a support coupling 140. The first and second jaw members 138a, 138b are here meshingly interengagable so that a tight clamp action can be produced without the first and second jaw members 138a, 138b clashing with one another physically.

The rail engagement jaws 132 may be closed automatically, for example, if driven by a motor, but in the depicted embodiment, are provided with a locking pin 142 which enables the rail engagement jaws 132 to be locked in the closed condition.

In the closed condition of the rail engagable jaws 132, a void 144 between the first and second jaw members 138a, 138b is or is substantially rectilinear so as to correctly engage with the head of a rail 20 in-use. However, whilst this is a preferred arrangement for rail engagable jaws 132, it will be appreciated that other grabs or tackle could be affixed to a winch of the rail engagement head 18 in order to couple to alternative rail components.

A more detailed view of the trolley support stand 66 is shown in Figure 19. The trolley support stand 66 comprises a ground support portion 146 and a trolley support portion 148 which is in- use above the ground support portion 146. In the depicted embodiment, the ground support portion 146 and trolley support portion 148 are releasably engagable with one another, and preferably telescopically so. This allows the position of a cross-member connector 150 of the trolley support portion 148 to be vertically adjusted with respect to the cross-member 16 with which it is to be engaged. A locking member, such as the locking pin 152 shown, may be used to lock the relative positions of the ground support portion 146 and a trolley support portion 148 with respect to one another. An adjustment mechanism may also be provided, which may be via a drivable member operated by a user control element, such as the control wheel 154 indicated.

The ground support portion 146 is formed having an engagement connector 156 which is dimensioned to engage with the trolley support portion 148, and which is supported by at least one foot 158, preferably at least two feet 158 to provide balance to the trolley support stand 66.

Figure 20 shows, in the inset, the drivable member of the trolley support stand 66, which may comprise a jack having a screw-threaded shaft 160 for raising and lowering a relative position of the trolley support portion 148 with respect to the ground support portion 146, and these components may be housing within the body of the trolley support portion 148. The screw- threaded shaft 160 can engage with a nut 162 fixed to the top of the inner tube section of the trolley support portion 148.

The cross-member connector 150 is preferably dimensioned so as to be formed equivalently to the hook portion 118 and locator nub 120 of the cross-member extender 64, and is therefore suitable for direct connection with the interface connector 72 of the cross-member 16 and/or interface connector 122 of the cross-member extender 64.

Figures 21 to 26 show the process for using a trolley support stand assembly 164 to extend the length of the cross-member 16 using the cross-member extender 64, and then engaging with a trolley support stand 66. This allows for the rail trolley 10 to be used in conjunction with, for instance, a third rail 20’. The brakes can be applied, preferably automatically in the absence of user intervention

Firstly, the or each rail trolley 10 is moved into position at or adjacent to a third rail 20’, as is illustrated in Figure 21. A cross-member extender 64 can then be engaged with the interface connector 72 of the cross-member 16 on a side which is proximate to the third rail 20’. Figures 24 to 24 show how the cross-member extender 64 of the depicted embodiment is levered into position such that the hook portion 118 and locator nub 120 correctly engage with the interface connector 72 of the cross-member 16.

Once the cross-member extender 64, or indeed extenders, is in position and the cross-member 16 has been extended to the desired length, the trolley support stand 66 can be connected to the cross-member extender 64 and adjusted to the correct height so that the rail engagement head 18 is level. This can be seen in Figure 25.

It may, however, be preferable to disengage the user engagement handle 24, use the trolley support stand 66 to jack up one end of the rail trolley 10, to thereby allow an intermediate wheel assembly 14b to be removed, as is shown in Figure 26. This allows the rail engagement head 18 to traverse the full extended length of the cross-member 16 without impediment by the said wheel assembly 14b. The rail engagement head 18 can therefore be aligned with the third rail 20’. The brakes and the friction between the trolley support stand 66 and the ground then serve to prevent movement of the rail trolley 10.

Whilst the term rail trolley is here used to describe a push vehicle suited to picking up of rails for repair or maintenance purposes, it will be appreciated that many of the improvements described could be utilised for rail vehicles, particularly manual vehicles, which have other applications within the rail industry.

It is therefore possible to provide an improved rail trolley apparatus when compared with equivalent rail trolley apparatuses known in the art. This is achieved by the provision of an improved braking system, improved wheel construction, and/or the provision of an extender which allows for the rail trolley to be used with a third rail outside of a standard rail track.

The words ‘comprises/comprising’ and the words ‘having/including’ when used herein with reference to the present invention are used to specify the presence of stated features, integers, steps or components, but do not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof.

It is appreciated that certain features of the invention, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable sub-combination. The embodiments described above are provided by way of examples only, and various other modifications will be apparent to persons skilled in the field without departing from the scope of the invention as defined herein.

Claims

1. A rail-trolley rail wheel (30) for movably supporting a rail trolley (10) on a rail, the rail wheel comprising:

an outer wheel body portion (46) having a circumferentially extending tread wall (42) for defining a tread of the rail wheel (30); and

an inner wheel body portion (48) which is at least in part receivable inside the outer wheel body portion (46), the inner wheel body portion (48) including a radial support wall (50) which buttresses at least part of the tread wall (42) of the outer wheel body (46).

2. A rail-trolley rail wheel (30) as claimed in claim 1 , wherein at least one of the outer and inner wheel body portions (46, 48) is formed from iron, steel, or an alloy thereof.

3. A rail-trolley rail wheel (30) as claimed in claim 2, wherein the outer and inner wheel body portions (46, 48) comprise spun steel.

4. A rail-trolley rail wheel (30) as claimed in any one of the preceding claims, wherein the tread wall (42) and/or radial support wall (50) is formed from sheet material.

5. A rail-trolley rail wheel (30) as claimed in any one of the preceding claims, the outer and inner wheel body portions (46, 48) contiguously meet to form a flange (44) of the rail wheel (30).

6. A rail-trolley rail wheel (30) as claimed in any one of the preceding claims, wherein the inner wheel body portion (48) forms a brake drum for the rail wheel (30).

7. A rail-trolley rail wheel (30) as claimed in any one of the preceding claims, further comprising a bearing receiver (54) which extends axially through the tread wall (42) and/or radial support wall (50).

8. A rail-trolley rail wheel (30) as claimed in claim 7, wherein the radial support wall (50) abuts the bearing receiver (54).

9. A rail-trolley rail wheel (30) as claimed in any one of the preceding claims, wherein the inner wheel body portion (48) further comprises an axial wall portion (52) connected to the radial support wall (50) which is in contact with at least part of the tread wall (42).

10. A rail-trolley rail wheel (30) as claimed in claim 9, wherein the axial wall portion (52) is conical or frusto-conical.

1 1. A rail-trolley fail-safe brake assembly (76) comprising:

a rail wheel (30) having a brake drum (78);

a brake shoe (80) receivable in the brake drum (78) for applying a braking force the rail wheel (30);

a brake-engagement member (82) to which the brake shoe (80) is mounted, the brake-engagement member (82) being pivotable between a braking condition and a release condition of the brake shoe (80) with respect to the brake drum (78), the brake- engagement member (82) having a cantilevered indicator arm (84); and

a biasing element (86) for biasing the brake shoe (80) towards the brake drum (78), a biased position of the cantilevered indicator arm (84) being indicative of a wear on the brake shoe (80).

12. A rail-trolley fail-safe brake assembly (76) as claimed in claim 11 , further comprising an actuation assembly (88) which is engagable with the brake-engagement member (82) for activating the release condition of the brake shoe (80).

13. A rail-trolley fail-safe brake assembly (76) as claimed in claim 12, wherein the actuation assembly (88) is engagable with the cantilevered indicator arm (84).

14. A rail-trolley fail-safe brake assembly (76) as claimed in claim 12 or claim 13, wherein two said rail wheels (30), brake shoes (80), brake-engagement members (82) and biasing elements (86) are provided, the actuation assembly (88) being engagable with both of the cantilevered indicator arms (84).

15. A rail-trolley fail-safe brake assembly (76) as claimed in claim 14, wherein the cantilevered indicator arms (84) are aligned to one another, a relative displacement of the cantilevered indicator arms (84) being indicative of a relative wear between the two brake shoes (80).

16. A rail-trolley fail-safe brake assembly (76) as claimed in any one of claims 12 to 15, further comprising a rail hook (90) which is coupled to the actuation assembly (88) and which is movable between an engaged condition in the braking condition of the brake shoe (80) and a disengaged condition in the release condition of the brake shoe (80).

17. A rail-trolley fail-safe brake assembly (76) as claimed in any one of claims 11 to 16, wherein the or each rail wheel (30) is formed from spun steel.

18. A rail trolley (10) comprising a chassis (28) and at least one rail-trolley fail-safe brake assembly (76) as claimed in any one of claims 11 to 17, wherein the chassis (28) includes an indicator port (106) at or adjacent to the or each cantilevered indicator arm (84) to permit visual inspection thereof.

19. A rail trolley (10) for moving railway components on a railway track, the rail trolley comprising:

a left-hand wheel assembly (14a) having first and second rail wheels (30) for engagement with a left-hand rail of the railway track and including a left-hand brake assembly (76) for releasably braking the first and second wheels (30);

a right-hand wheel assembly (14b) having third and fourth wheels (30) for engagement with a right-hand rail of the railway track and including a right-hand brake assembly (76) for releasably braking the third and fourth wheels;

a cross-member (16) which extends between the left-hand and right-hand wheel assemblies (14a, 14b);

a brake control member positioned on the cross-member (16) configured to operate the left-hand and right-hand brake assemblies (76) simultaneously.

20. A rail trolley (10) as claimed in claim 19, wherein the brake control member extends across the full extent of the cross-member (16).

21. A rail trolley (10) as claimed in claim 19 or claim 20, wherein the brake control member is a movable bar (26).

22. A rail trolley (10) as claimed in any one of claims 19 to 21 , wherein the first, second, third and fourth wheels (30) are formed from spun steel.

23. A rail trolley (10) as claimed in any one of claims 19 to 24, wherein the left- and/or right- hand brake assemblies (76) are rail-trolley fail-safe brake assemblies as claimed in any one of claims 1 1 to 17.

24. A rail trolley system for moving railway components on a railway track, the rail trolley (10) comprising:

a left-hand wheel assembly (14a) having first and second rail wheels (30) for engagement with a left-hand rail of the railway track;

a right-hand wheel assembly (14b) having third and fourth rail wheels (30) for engagement with a right-hand rail of the railway track; a cross-member (16) which extends between the left-hand and right-hand wheel assemblies (14a, 14b) and having an engagement connector (156) which extends outwardly past at least one of the left-hand and right-hand wheel assemblies (14a, 14b); and

a trolley support stand assembly which is demountably engagable with the engagement connector (156) of the cross-member (16) to permit the rail trolley (10) to be supported on the ground.

25. A rail trolley system as claimed in claim 24, wherein the trolley support stand assembly comprises a trolley support stand (66) and a cross-member extender (64), the cross member extender (64) being engagable with the engagement connector (156) and the trolley support stand (66) to extend the length of the cross-member (16).