Railway points, railway points operating apparatus and railway track crossing

Abstract

A railway points arrangement 10 for a railway track junction comprises at least first and second pairs of longitudinally-extending, parallel-spaced static stock rails 12, 14, defining respectively a first route and a second route, and a pair of longitudinally-extending, parallel-spaced switch rails 16 which are movable between a first position in alignment with the first pair of stock rails 12 to select the first route and a second position in alignment with the second pair of stock rails 14 to select the second route. At least one of the movable switch rails 16a cooperates with at least one stock rail 12, 14 of each of the first and second pairs of stock rails 12, 14 when the movable switch rails 16 are in the first and second positions, and the at least one switch rail 16 and the at least one stock rail 12, 14 are shaped to define a mating profile 50 which aligns the switch rail 16 and stock rail 12, 14 and prevents transverse movement of the switch rail 16 relative to the stock rail 12, 14.

Claims

1. A railway points arrangement for a railway track junction, the railway points arrangement comprising: at least first and second pairs of longitudinally-extending, parallel-spaced static stock rails defining respectively a first route and a second route; and a pair of longitudinally-extending, parallel-spaced switch rails movable vertically and transversely between a first transverse position in alignment with the first pair of stock rails to select the first route and a second transverse position in alignment with the second pair of stock rails to select the second route; wherein at least one of the movable switch rails cooperates with at least one stock rail of the first pair of stock rails when the movable switch rails are in the first transverse position and with at least one stock rail of the second pair of stock rails when the movable switch rails are in the second transverse position, said at least one switch rail and said at least one stock rail being shaped to define a mating profile which aligns the switch rail and stock rail and prevents transverse movement of the switch rail relative to the stock rail when the switch rails are in the first transverse position or the second transverse position, the mating profile being formed by an upper surface of the stock rail and a lower surface of the switch rail, and wherein the mating profile is arranged to permit said at least one switch rail to be moved in a vertical direction relative to said at least one stock rail to engage and disengage the mating profile and thereby permit transverse movement of the switch rails between the first and second transverse positions.

2. The points arrangement according to claim 1, wherein the mating profile is arranged to permit relative longitudinal movement between said at least one switch rail and said at least one stock rail when the switch rails are in the first and second transverse positions.

3. The points arrangement according to claim 1, wherein the mating profile comprises a convex profile section and a complementary concave profile section.

4. The points arrangement according to claim 3, wherein the convex profile section extends upwardly from said at least one stock rail and the concave profile section is formed in said at least one switch rail.

5. The points arrangement according to claim 1, wherein an expansion gap is defined between the facing end surfaces of said at least one switch rail and said at least one stock rail when the switch rails are in the first and second transverse positions.

6. The points arrangement according to claim 1, wherein said at least one switch rail and said at least one stock rail are tapered in the longitudinal direction to define a mitred connection that permits relative longitudinal movement between said at least one switch rail and said at least one stock rail.

7. A railway points operating apparatus for a railway points arrangement comprising at least first and second pairs of longitudinally-extending, parallel-spaced static stock rails defining respectively a first route and a second route and a pair of longitudinally extending switch rails movable between a first position to select the first route and a second position to select the second route, wherein the railway points operating apparatus comprises: an actuator arrangement for moving the switch rails transversely and vertically about an arc between the first and second positions so that the switch rails are raised and lowered relative to the stock rails during said transverse movement; a locking arrangement for preventing transverse horizontal movement of the switch rails from the first and second positions; and a support member having an upper surface on which the switch rails are mounted in a spaced relationship, the actuator arrangement being arranged to move the support member about said arc to move the switch rails between the first and second positions, the support member having a lower surface and a plurality of transversely spaced recesses provided on said lower surface.

8. The points operating apparatus according to claim 7, wherein the locking arrangement includes an upwardly extending locking projection which locates in one of said transversely spaced recesses when the switch rails are in the first and second positions to prevent transverse horizontal movement of the support member.

9. The points operating apparatus according to claim 8, wherein the locking projection has a substantially semi-circular profile which is complementary to the semi-circular profile of each recess.

10. The points operating apparatus according to claim 7, wherein the actuator arrangement includes an actuating member which cooperates with the support member to move the support member about said arc and thereby move the switch rails between the first and second positions, the actuating member cooperates with the transversely spaced recesses to move the support member about said arc, and the actuating member is disengaged from the transversely spaced recesses when the switch rails are in the first and second positions.

11. The points operating apparatus according to claim 10, wherein the actuating member comprises a rotatable cam member.

12. A railway track crossing comprising: a fixed crossing nose formed by a pair of diverging rails; a pair of independently movable rails each having a wing rail section provided on each side of the fixed crossing nose, each rail being movable transversely from a closed position in which the wing rail section contacts the crossing nose to an open position in which the wing rail section is spaced from the crossing nose to form a groove that allows the passage of a wheel flange between the crossing nose and the wing rail section; and an actuator arrangement which is operable to move a selected one of the movable rails from the closed position to the open position, each movable rail being arranged to adopt the closed position in the absence of any force applied to it by the actuator arrangement due to the inherent stiffness and natural bend of the movable rail; wherein: each movable rail includes a first mating feature; the railway track crossing includes a locking element, positioned beneath each movable rail, which includes a second mating feature; and the first mating feature cooperates with the second mating feature to lock the movable rail in the closed position when the movable rail is loaded by the wheels of rolling stock passing through the railway track crossing.

13. The railway track crossing according to claim 12, wherein each movable rail adopts a first position in which the wing rail section is elevated above the crossing nose when the movable rail is unloaded and each movable rail is arranged to move downwardly to a second position when the movable rail is loaded by the wheels of rolling stock passing through the railway track junction, the first and second mating features being arranged to cooperate when the movable rail is loaded and thereby moved to the second position.

14. The railway track crossing according to claim 13, wherein a running surface of the wing rail section is substantially coplanar with a running surface of the crossing nose when the movable rail is loaded and in the second position.

15. The railway track crossing according to claim 13, wherein the railway track crossing includes a plurality of dampers, at least one damper being arranged to retard the movement of each movable rail from the second position to the first position, and the damper is arranged to retard the movement of the movable rail from the open position to the closed position.

16. The railway track crossing according to claim 12, wherein the railway track crossing includes a plurality of biasing means, the biasing means are arranged to bias each movable rail into the elevated first position when each movable rail is not loaded by the wheels of rolling stock, and the biasing means are arranged to bias each movable rail into the closed position.

17. The railway track crossing according to claim 12, wherein the first and second mating features comprise a longitudinally extending concave profile section and a complementary longitudinally extending convex profile section.

18. The railway track crossing according to claim 17, wherein the convex profile section extends downwardly from a lower flange of each movable rail and the concave profile section opens upwardly to accommodate the convex profile section when the movable rail is in the second position.

19. The railway track crossing according to claim 17, wherein each movable rail adopts a first position in which the wing rail section is elevated above the crossing nose when the movable rail is unloaded and each movable rail is arranged to move downwardly to a second position when the movable rail is loaded by the wheels of rolling stock passing through the railway track junction, the first and second mating features being arranged to cooperate when the movable rail is loaded and thereby moved to the second position, the convex profile section and the concave profile section each include a bearing surface configured to guide each movable rail downwardly to the second position when the movable rail is loaded by the wheels of rolling stock passing through the railway track crossing, and the bearing surface is configured to guide each movable rail upwardly, from the first position to a third position that is elevated above the first position, when the movable rail is moved from the closed position to the open position.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a diagrammatic perspective view of a railway points arrangement according to the present disclosure comprising switch rails and stock rails;

(2) FIG. 2 is an enlarged diagrammatic perspective view of one of the stock rails shown in FIG. 1;

(3) FIG. 3 is an enlarged diagrammatic perspective view of one of the switch rails shown in FIG. 1;

(4) FIG. 4 is a diagrammatic cross-sectional view of the regional labelled A in FIG. 1 showing one possible form of mating profile between the switch rail and the stock rail;

(5) FIG. 5 is a diagrammatic plan view of one possible form of points arrangement in the form of a stub switch and including a plurality of points operating apparatus according to the present disclosure;

(6) FIG. 6 is a detailed diagrammatic plan view of the points operating apparatus;

(7) FIG. 7 is a diagrammatic view similar to FIG. 6 with the switch rails and support member for the switch rails omitted;

(8) FIG. 8 is a diagrammatic cross-sectional side view of the points operating apparatus of FIGS. 6 and 7 in a configuration in which it locates the switch rails in a first position;

(9) FIGS. 9 to 12 illustrate the operation of the points operating apparatus as it moves the switch rails from the first position shown in FIG. 8 to a second position shown in FIG. 12;

(10) FIG. 13 is a diagrammatic cross-sectional side view of the points operating apparatus similar to FIG. 8 but in a configuration in which it locates the switch rails in a third position;

(11) FIG. 14 is a diagrammatic plan view similar to FIG. 7 of an alternative embodiment of a points operating apparatus;

(12) FIG. 15 is a diagrammatic cross-sectional side view of the points operating apparatus shown in FIG. 14;

(13) FIG. 16 is a plan view of a railway track junction including a set of railway points and a conventional fixed railway track crossing;

(14) FIG. 17 is a plan view of a railway track crossing according to the present disclosure in which each of the movable rails is in a closed position;

(15) FIG. 18 is a view similar to FIG. 17 in which the railway track crossing is set for the straight route shown in FIG. 16 with one of the movable rails in an open position;

(16) FIG. 19 is a view similar to FIGS. 17 and 18 in which the railway track crossing is set for the turnout route shown in FIG. 16 with the other of the movable rails in an open position;

(17) FIGS. 20 and 21 are cross-sectional views respectively along the lines A-A and B-B of FIG. 17;

(18) FIGS. 22 and 23 are cross-sectional views respectively along the lines C-C and D-D of FIG. 18 showing the movable rail in the closed position in an unloaded state;

(19) FIGS. 24 and 25 are cross-sectional views similar to FIGS. 22 and 23 showing the movable rail loaded by a wheel of passing rolling stock;

(20) FIG. 26 is an enlarged plan view of part of an actuator arrangement; and

(21) FIG. 27 is a perspective view of an actuating member.

DETAILED DESCRIPTION OF EMBODIMENTS

(22) Embodiments of the present disclosure will now be described by way of example only and with reference to the accompanying drawings.

(23) FIG. 1 illustrates a railway points arrangement 10 for a railway track junction which enables different routes to be selected through the junction. The points arrangement 10 comprises first and second pairs of longitudinally-extending, parallel-spaced static stock rails 12, 14 mounted on fixed supports 15 in the form of sleepers or bearers. The stock rails 12, 14 have running surfaces 12c, 14c. The first pair of stock rails 12 defines a first route, for example a straight route. The second pair of stock rails 14 defines a second route, for example a turnout route.

(24) The points arrangement 10 also includes a pair of longitudinally-extending, parallel-spaced switch rails 16 having running surfaces 16c. In FIG. 1, the switch rails 16 are shown in a first transverse position in which they are aligned with the first pair of stock rails 12 and have coplanar running surfaces 16c, 12c thus enabling rolling stock to follow the first route through the railway track junction. As will be explained in further detail below, the switch rails 16 can be moved between the illustrated first transverse position and a second transverse position in which they are aligned with the second pair of stock rails 14 and have coplanar running surfaces 16c, 14c thus enabling rolling stock to follow the second route through the railway track junction.

(25) Although not illustrated in FIG. 1, it will be appreciated that the stock rails 12, 14 and the switch rails 16 are secured to plain line rails which define the respective route either side of the railway track junction, for example the straight route and the turnout route. The stock rails 12, 14 and switch rails 16 could, for example, be secured to the plain line rails by suitable fastenings which are passed through openings 18 provided in a web section of each rail 12, 14, 16 and which engage in corresponding openings in a fish plate arrangement that is also secured to the plain line rails. Alternatively, the stock rails 12, 14 and switch rails 16 could be secured to the plain line rails by welding, in which case openings 18 do not need to be provided in the web section.

(26) Referring now to FIGS. 1 to 4, the switch rails 16 cooperate with the stock rails 12, 14 when the switch rails 16 are in the first position (shown in FIG. 1) and the second position (not shown). In particular, the switch rails 16 and stock rails 12, 14 are shaped to define a mating profile 50 (see FIG. 4) which aligns the switch rails 16 with the stock rails 12, 14 and prevents the switch rails 16 from moving transversely, in the horizontal direction, relative to the stock rails 12, 14. The mating profile 50 is formed by an upper surface 54 of the stock rails 12, 14 and a lower surface 56 of the switch rails 16 and the particular arrangement and geometry of the mating profile 50, a preferred embodiment of which will be explained in further detail below with respect to one of the switch rails 16 and stock rails 12, acts as a passive self-alignment and locking feature which ensures that the switch rails 16 and the stock rails 12, 14 are always accurately aligned and locked transversely when the switch rails 16 are in either the first position or the second position.

(27) The stock rail 12, 14 includes a base portion 20 having upwardly sloped converging surfaces 22, 24, acting as the upper surface 54, which define an upwardly extending convex profile section 26 extending longitudinally along at least part of the stock rail 12. Similarly, the switch rail 16 includes a concave profile section 32 defined by upwardly sloped converging surfaces 28, 30 which act as the lower surface 56. The convex profile section 26 is accommodated in the concave profile section 32 when the switch rails 16 are in the first and second positions and the switch rail 16 is thus constrained against movement in the transverse horizontal direction. In the illustrated embodiment, the convex profile section 26 and the concave profile section 32 form an inverted generally V-section profile 50. Other configurations, such as an inverted generally U-section profile, are however possible.

(28) In order to move the switch rails 16 between the first and second positions, an actuator arrangement (not shown) is used to raise the switch rails 16 by at least a distance which is sufficient to disengage the convex profile section 26 from the concave profile section 32. The actuator arrangement transversely and vertically moves the switch rails 16 to a position in which they are transversely and vertically aligned with either the first pair of stock rails 12 or the second pair of stock rails 14 depending on the desired route, the switch rails 16 being lowered to engage the convex profile section 26 in the concave profile section 32. Any suitable actuator arrangement can be used to raise/lower and move the switch rails 16 transversely between the first and second positions. A particularly suitable actuator arrangement is described later in this specification with reference to FIGS. 5 to 15.

(29) In accordance with aspects of the present disclosure, when the switch rails 16 are moved between the first and second positions, the actuator arrangement does not need to move the switch rails 16 to a position in which they are perfectly transversely aligned with the stock rails 12, 14. This is because the cooperation between the sloped mating surfaces 22, 28 and 24, 30 guides the switch rails 16 transversely and downwardly, for example about an arcuate path, into a position in which the running surfaces 16c, 12c, and 16c, 14c are coplanar and the switch rails 16 and stock rails 12, 14 are transversely aligned. The mating surfaces 22, 28 and 24, 30 thus ensure that the switch rails 16 are always in proper alignment with the stock rails 12, 14 when the switch rails 16 are in the first or second position.

(30) In order to allow a gradual transfer of rolling forces between the running surface 16c (in particular the running edges 16b) of the switch rails 16 and the running surfaces 12c, 14c (in particular the running edges 12b, 14b) of the stock rails 12, 14, the switch rails 16 and stock rails 12, 14 are shaped to provide a mitred connection 38. As can be clearly seen in FIG. 1, the mitred connection 38 provides a continuous and smooth running edge surface for rolling stock passing the railway track junction.

(31) In the illustrated embodiment, the mitred connection 38 is defined by cooperating pairs of substantially vertical faces 40a, 40b, 42a, 42b and 44a, 44b which may also help to transversely align the switch rails 16 and the stock rails 12, 14. Any suitable geometry can, however, be adopted to form the mitred connection.

(32) The stock rails 12, 14 and the switch rails 16 have pairs of facing end surfaces 48a, 48b and 50a, 50b. The respective pairs of facing end surfaces 48a, 48b and 50a, 50b are spaced from each other when the switch rails 16 are in the first and second positions to define expansion gaps 52 which are best seen in FIG. 1. These gaps 52 ensure that if there is longitudinal thermal expansion of the stock rails 12, 14 and/or the switch rails 16, the ends of the switch rails 16 do not become jammed or fouled against the ends of the stock rails 12, 14.

(33) FIG. 5 illustrates a railway points arrangement 110 for a railway track junction which enables different routes to be selected through the junction. The illustrated points arrangement 110 takes the form of a conventional stub switch and comprises first and second pairs of longitudinally-extending, parallel-spaced static stock rails 112, 114 mounted on fixed supports in the form of sleepers or bearers (not shown). The first pair of stock rails 112 defines a first route, in the illustrated arrangement straight route. The second pair of stock rails 114 defines a second route, in the illustrated arrangement a right turnout route. Although not shown in FIG. 5, one or more further pairs of stock rails could be provided to define further diverging routes. For example, a pair of stock rails could be provided which define a third route in the form of a left turnout route.

(34) The points arrangement 110 comprises a pair of longitudinally-extending, parallel-spaced switch rails 116 which can bend transversely about a generally fixed end 118 where the switch rails 116 are secured to plain line rails 120. In FIG. 5, the switch rails 116 are shown in a first position with the free ends of the switch rails 116 aligned with the ends of the first pair of stock rails 112, thus enabling rolling stock to follow the first (straight) route through the railway track junction. The switch rails 116 can be moved between the illustrated first position and a second position in which the free ends of the switch rails 116 are aligned with the ends of the second pair of stock rails 114, thus enabling rolling stock to follow the second (right turnout) route through the railway track junction. Similarly, the switch rails 116 can be moved to other positions in which the free ends of the switch rails 112 are aligned with the ends of other pairs of stock rails thus enabling rolling stock to follow other diverging routes through the railway track junction, such as the third (left turnout) route mentioned above but not illustrated.

(35) In order to move the switch rails 116 between different positions, for example between the first and second positions, and to ensure that the switch rails 116 are properly aligned with the first and second pairs of stock rails 112, 114 when they are in the first and second positions, a plurality of points operating apparatus 122 is provided. As shown in FIG. 5, it is preferable that the points operating apparatus 122 are provided at longitudinally spaced positions along the switch rails 116 to ensure that the switch rails 116 are adequately supported and aligned along their length and to ensure that the necessary degree of redundancy is provided. Redundancy is desirable so that the points arrangement 110 can continue to operate in the event of failure of, for example, one of the points operating apparatus 122. Although three points operating apparatus 122 are shown in FIG. 5, this is illustrative only and any suitable number of points operating apparatus can be provided.

(36) Referring now to FIGS. 6 to 8, the points operating apparatus 122 comprises a housing 124 having a support member 126 in the form of a bearer which is positioned underneath the switch rails 116 and which forms the top of the housing 124. The switch rails 116 are removably secured, for example by suitable mounts 128, in a predetermined spaced relationship to the upper surface of the support member 126 and the support member 126 thus supports and moves the switch rails 116. The support member 126 has two pairs of longitudinally spaced plate members 130 on its lower surface. Each pair of plate members 130 is located at a position substantially beneath the switch rails 116 and has three transversely spaced and downward facing recesses 132. The recesses 132 each have a bearing surface 134 which has a substantially semi-circular or inverted U-shaped profile.

(37) The points operating apparatus 122 comprises an actuator arrangement 135 which moves the support member 126, and hence the switch rails 116, between different positions, for example first, second and third positions, to select different routes through the railway track junction. Rather than moving the switch rails 116 in a transverse horizontal direction as is conventional in the prior art, the actuator arrangement 135 moves the support member 126, and hence the free ends of the switch rails 116, transversely and vertically about a semi-circular arc between different positions so that the free ends of the switch rails 116 are raised and lowered relative to the stock rails 112, 114 during the transverse switching movement. In practice, this transverse and vertical movement of the free ends of the switch rails 116 is achieved by bending the switch rails 116.

(38) The actuator arrangement 135 comprises a drivetrain for rotating an actuating member in the form of a cam member 136 which can be selectively engaged in the recesses 132 to move the support member 126, and hence the switch rails 116, about the semi-circular arc between the first and second positions. The drivetrain comprises an electric motor 138 which is connected, by a backdrivable gearbox 140, to a primary driveshaft 142. Rotational motion is transmitted from the primary driveshaft 142 to a final driveshaft 144 by spur gears 146, 148 mounted respectively on each shaft 142, 144. One of the spur gears 146, 148 may include a slip clutch (not shown) having a predetermined slip torque. Rotational motion is transmitted from the final driveshaft 144 to cam shafts 150a, 150b by a crown and pinion gear arrangement 152a, 152b located at each end of the final driveshaft 144. Each cam shaft 150a, 150b carries two longitudinally spaced cam members 136. Each cam member 136 has a lobe which provides a bearing surface 154 which is complementary to the bearing surface 134 of each recess 132 and which cooperates with the bearing surface 134 of each recess 132 when the cam members 136 are engaged in the recesses 132.

(39) The points operating apparatus 122 further comprises a locking arrangement 156 which securely retains the support member 126, and hence the switch rails 116, in a selected transverse position (such as the first, second or third position) and prevents movement of the support member 126 from the selected position in a transverse horizontal direction. Movement of the support member 126, and hence the switch rails 116, from the selected position can be effected only when the support member 126 is urged to move by the actuator arrangement about the aforementioned semi-circular arc.

(40) The locking arrangement 156 comprises two pairs of longitudinally spaced locking projections 158 which are fixed to, and extend upwardly from, a base of the housing 124. Each locking projection 158 has a bearing surface 160 with a substantially semi-circular or inverted U-shaped profile which is complementary to the bearing surfaces 134 of the recesses 132.

(41) FIG. 8 shows the points operating apparatus 122 in a first configuration in which the switch rails 116 are in a first, central, position aligned, for example, with the first pair of stock rails 112 illustrated in FIG. 5 to select the straight route. FIG. 12 shows the points operating apparatus 122 in a second configuration in which the switch rails 116 are in a second position aligned, for example, with the second pair of stock rails 114 illustrated in FIG. 5 to select the right turnout route. It will be noted that when the points operating apparatus 122 is in either of these configurations or indeed similar configurations in with the switch rails 116 are set for any given route, the cam members 136 are disengaged from the recesses 132 whereas the locking projections 158 are fully engaged in the recesses 132. It will, therefore, be apparent that the actuator arrangement 135, in particular the cam members 136, plays no part in locking the support member 126, and hence the switch rails 116, in a selected position. This locking is achieved solely by virtue of the cooperation between the locking projections 158 and the recesses 132.

(42) The operation of the points operating apparatus 122 will now be explained with reference to FIGS. 8 to 12 when the switch rails 116 are moved between the first and second positions.

(43) The electric motor 138 is operated to rotate the primary driveshaft 142 via the gearbox 140. This in turn rotates the final driveshaft 144, via the spur gears 146, 148, thereby rotating the cam shafts 150a, 150b via the crown and pinion gear arrangements 152a, 152b. The cam members 136 are thus rotated in the clockwise direction into a position in which they engage the corresponding recesses 132 in the plate members 130 as shown in FIG. 9. Continued clockwise rotation of the cam members 136 moves the support member 126, and hence the switch rails 116, upwardly and transversely towards the right to commence the semi-circular motion as shown in FIG. 10. During this semi-circular motion, the locking projections 158 are progressively disengaged from the recesses 132, the cooperation between the bearing surfaces 134 and 160 facilitating this disengagement. Further clockwise rotation of the cam members 136 continues the semi-circular motion of the support member 126 and the switch rails 116, as shown in FIG. 11. Once the support member 126 has reached the position shown in FIG. 11, the inherent stiffness of the switch rails 116 (and possibly the mass of the switch rails 116 depending on their length) tends to urge them downwardly, along the semi-circular arc which is dictated by the rotational motion of the cam members 136 on the camshafts 150a, 150b. The support member 126 is, therefore, also urged downwardly along the same semi-circular arc and as the switch rails 116 approach the second position, the locking projections 158 progressively engage in the recesses 132, this engagement being facilitated by the cooperation between the bearing surfaces 134 and 160. Advantageously, the semi-circular profile of the bearing surfaces 134, 160 tends to align the support member 126 transversely as it completes its semi-circular motion and this helps to ensure that the switch rails 116 are correctly aligned with the stock rails 114 when the switch rails 116 are in the second position. As shown in FIG. 12, rotation of the cam members 136 continues until the cam members 136 are completely disengaged from the recesses 132.

(44) It will be understood that a different route, such as the left turnout route, can be selected in a similar manner, for example by operating the electric motor 138 to rotate the cam members 136 in the anti-clockwise direction to move the support member 126 and hence the switch rails 116 from the position shown in FIG. 8 to the position shown in FIG. 13.

(45) It will be noted that the key components of the points operating apparatus 122 are all positioned inside the housing 124 and therefore protected from the external environment. This improves the reliability of the apparatus 122. In order to permit the support member 126 to follow the semi-circular path and at the same time maintain the sealed environment inside the housing 124, the apparatus 122 includes movable or flexible flap members 123 which can move upwardly and downwardly, as best shown in FIGS. 8 to 12, in concert with the movement of the support member 126.

(46) FIGS. 14 and 15 illustrate an alternative embodiment of the points operating apparatus 1122 which is similar to the points operating apparatus 122 shown in FIGS. 6 to 13 and in which corresponding components are identified using corresponding reference numerals.

(47) The points operating apparatus 1122 utilises a modified drivetrain based on a rack-and-pinion arrangement. In more detail, the electric motor 138 and gearbox 140 rotate a pinion gear 162 which cooperates with a transversely extending and transversely movable rack gear 164 to thereby move the rack gear 164. Each of the cam shafts 150a, 150b also carries a pinion gear 166a, 166b which cooperates with the rack gear 164. It will be apparent that upon movement of the rack gear 164 in the transverse direction, the pinion gears 166a, 166b are rotated thereby causing corresponding rotation of the camshafts 150a, 150b and the cam members 136. Although the points operating apparatus 1122 utilises a modified drivetrain, it will be immediately apparent that the motion of the support member 126, and hence the motion of the switch rails 116, is the same as described above with reference to FIGS. 8 to 13. Accordingly, no further explanation is needed.

(48) The points operating apparatus 122, 1122 has been described in conjunction with a standard stub switch in which the free ends of the switch rails 116 do not cooperate with the ends of the stock rails 112, 114 when the switch rails 116 are in the first or second positions or indeed in any other position (such as a third position). In such conventional stub switches, there is no strict requirement to raise the switch rails 116 in order to effect transverse movement between different positions, such as the first, second and third positions, but this might be advantageous for the reasons mentioned earlier in this specification.

(49) A points arrangement 10 which is based on the standard stub switch but in which the free ends of the switch rails 16 cooperate with the stock rails 12, 14 when the switch rails 16 are in different positions, set for different routes, has been described above with reference to FIGS. 1 to 4. In a preferred embodiment of the railway points arrangement 10, the free ends of the switch rails 16 have to be raised to disengage them from the stock rails 12, 14 to enable the switch rails 16 to be moved transversely between different positions, for example first, second and third positions, to select different routes. It will, therefore, be apparent that the points operating apparatus 122, 1122 described with reference to FIGS. 5 to 15 is particularly, although not exclusively, suitable for use with the railway points arrangement 10 described with reference to FIGS. 1 to 4.

(50) It should also be noted for completeness that the points operating apparatus 122, 1122 is not exclusively intended for use with a points arrangement 110 in the form of a stub switch and that it can be used to move and lock the switch rails of a traditional points arrangement in which the switch rails are located between incoming stock rails and can move about a fixed end. In such a conventional points arrangement, the free ends of the switch rails can be moved transversely and vertically about an arc by the points operating apparatus 122, 1122 between a first position in which the free end of one of the switch rails contacts one of the incoming stock rails to select the first route and a second position in which the free end of the other switch rail contacts the other incoming stock rail to select the second route.

(51) FIGS. 17 to 27 illustrate a railway track crossing 240 according to the present disclosure. The railway track crossing 240 forms part of a railway track junction 210 such as that shown in FIG. 16 in place of the fixed railway track crossing 222.

(52) Referring initially to FIGS. 17 to 19, the railway track crossing 240 includes a v-section fixed crossing nose 242, formed by a pair of diverging rails 244, and a pair of movable rails 245 each having a wing rail section 246 provided on each side of the fixed crossing nose 242. The diverging rails 244 and movable rails 245 are mounted in a conventional manner on fixed supports 243 in the form of sleepers or bearers. The movable rails 245 include converging rail sections 249 which converge from a fixed end 248 towards a constriction 250. The wing rail sections 246, which form a continuation of the converging rail sections 249, diverge from the constriction 250 on each side of the fixed crossing nose 242 towards a free end 252. Each of the movable rails 245 is independently movable between a closed position, shown in FIGS. 17, 20 and 21, in which its wing rail section 246 contacts the crossing nose 242, and an open position, shown in FIGS. 18, 19, 22, 23, 24 and 25, in which its wing rail section 246 is spaced from the crossing nose 242. When each movable rail 245 is in the open position, a groove 254 (FIGS. 18, 19 and 25) is provided between the crossing nose 242 and the wing rail section 246 to allow the passage of a wheel flange 256a. As can be clearly seen in FIG. 17, each wing rail section 246 includes a flared section 258 at its free end 252 which is spaced from the crossing nose 242 when the movable rail 245 is in the closed position.

(53) An actuator arrangement 260 (see FIG. 26) is provided to move a selected one the movable rails 245 from the closed position to the open position by applying a transverse force to the selected movable rail 245. In the absence of any transverse force being applied to the movable rails 245 by the actuator arrangement 260, the movable rails 245 adopt the closed position shown in FIGS. 17 and 21 thereby placing the railway track crossing 240 in a neutral state. The actuator arrangement 260 includes an actuating member 262 located between the converging rail sections 249, at a position between the fixed ends 248 and the constriction 250.

(54) The actuator arrangement 260 includes an actuator arm 264 which cooperates at one end with the actuating member 262 by virtue of engagement of an upwardly projecting leg 266 in a recess 268 formed in the actuating member 262. The other end of the actuator arm 264 cooperates with a trackside controllable drive mechanism (not shown), such as an actuator bank including a plurality of backdrivable independent actuator drives. The controllable drive mechanism can be operated in a conventional manner to displace the actuator arm 264, and hence the actuating member 262, transversely. The actuating member 262 can consequently be moved transversely into contact with a selected one of the movable rails 245, and in particular the converging rail sections 249, and can thereby displace the selected movable rail 245 transversely from the closed position to the open position.

(55) When the movable rails 245 are in the closed position, they can move vertically between a first position, shown in FIGS. 20 and 21, and a second position, shown in FIGS. 24 and 25 (see the left movable rail 245). When the movable rails 245 are in the first position, the running surface 270 of the wing rail sections 246 is raised slightly above to the running surface 272 of the crossing nose 242. When the movable rails 245 are in the second position, the running surface 270 of the wing rail sections 246 is substantially coplanar with the running surface 272 of the crossing nose 242 thereby providing a continuous running surface for the wheels 256 of passing rolling stock.

(56) The railway track crossing 240 includes a plurality of biasing means 274 in the form of compression springs which are spaced longitudinally along the running direction of each movable rail 245. The primary purpose of the biasing means 274 is to bias the movable rails 245 into the elevated first position shown in FIGS. 20 and 21 and to thereby prevent the movable rails 245 from moving to the second position under their own weight (i.e. from sagging). Due to the inclination of the biasing means 274 in the illustrated embodiment, it will be appreciated that the biasing means 274 also help to bias the movable rails 245 into the closed position, such that the wing rail sections 246 are in contact with the crossing nose 242. Referring to FIGS. 24 and 25, it will be seen that when a selected one of the movable rails 245 is in the closed position and is loaded by the wheels 256 of rolling stock passing through the railway track crossing 240 (the left movable rail in FIGS. 24 and 25), the load applied to the movable rail 245 displaces it from the elevated first position to the second position thereby compressing the biasing means 274. After rolling stock has passed through the railway track crossing 240, the movable rail 245 is biased upwardly to the elevated first position by the biasing means 274.

(57) The railway track crossing includes a plurality of dampers 276 which, like the biasing means 274, are spaced longitudinally along the running direction of each movable rail 245. The dampers 276 retard the movement of the movable rails 245 in the upward direction, from the second position to the first position, and may also retard movement of the movable rails 245 from the open position to the closed position if the movable rails 245, and hence the wing rail sections 246, are incorrectly positioned for the desired route, as will be explained in further detail below.

(58) Each movable rail 245 includes a first mating feature 278 in the form of a convex profile section 280 which extends longitudinally along the running direction of each movable rail 245. The convex profile section 280 projects downwardly from a lower flange 247 of each movable rail 245. The railway track crossing 210 also includes a second mating feature 282 in the form of an upwardly opening concave profile section 284 which extends longitudinally along the running direction of each movable rail 245. In the illustrated embodiment, a longitudinally extending locking element 286 is positioned beneath the movable rails 245 and the concave profile sections 284 are formed at transversely spaced positions in the locking element 286. As can be clearly seen in FIGS. 24 and 25, when the movable rail 245 which is in the closed position is loaded by the wheels 256 of rolling stock passing through the railway track crossing 240 so that it is moved to the second position, the convex profile section 280 engages the concave profile section 284. This engagement prevents any transverse movement of the movable rail 245, and hence the wing rail section 246, and ensures that the movable rail 245 is locked in the closed position, with the wing rail section 246 in contact with the crossing nose 242, whilst it is loaded by the wheels 256 of passing rolling stock.

(59) Each convex profile section 280 includes a bearing surface 288 having a substantially semi-circular curved surface portion 288a provided by a shoulder 290 and a substantially linear surface portion 288b which is inclined upwardly away from the crossing nose 242 in the transverse direction. Each concave profile section 284 also includes a bearing surface 292 having a correspondingly shaped curved surface portion 292a and an upwardly inclined linear surface portion 292b. As will be clear from FIGS. 24 and 25, the various surface portions 288a, 288b, 292a, 292b of each bearing surface 288, 292 are in intimate contact when the movable rail 245 is in the second position. It is this intimate contact that locks the movable rail 245 in the closed position. When one of the movable rails 245 is moved from the closed position to the open position (i.e. the position adopted by the right hand movable rail 245 in FIGS. 22 to 25), the bearing surfaces 288, 292 cooperate to guide the movable rail 245 upwardly, from the first position to a third position which is elevated above the first position. More particularly, the curved surface portion 288a provided by the shoulder 290 contacts the curved surface portion 292a and the linear surface portion 292b thereby guiding the movable rail 245 upwardly.

(60) The operation of the railway track crossing 240 will now be described with reference to FIGS. 17 to 27 of the accompanying drawings.

(61) When it is not intended that rolling stock should pass through the railway track crossing 240 and, therefore, when the railway track crossing 240 is not in use, the controllable drive mechanism is set so that the actuating member 262 adopts a neutral transverse position in which it does not apply any force to either of the movable rails 245. As a result both of the movable rails 245 adopt the closed position illustrated in FIGS. 17, 20 and 21. Furthermore, in the absence of any load applied to the movable rails 245 by rolling stock, the movable rails 245 are biased into the elevated first position by the biasing means 274 so that the running surfaces 270 of the wing rail sections 246 are elevated slightly above the running surface 272 of the crossing nose 242 (see FIG. 21).

(62) When it is intended that rolling stock should pass through the railway track crossing 240, a points arrangement is operated in a conventional manner to move switch blades to select a desired route for the rolling stock. At the same time, the controllable drive mechanism is operated to displace the actuator arm 264, and hence the actuating member 262, transversely to move the appropriate one of the movable rails 245 from the closed position to the open position. This is best seen in FIGS. 18, 22 and 23 which illustrates the movement of the appropriate movable rail 245 to allow rolling stock to follow the straight route 212 illustrated in FIG. 16. The movement of the movable rail 245 opens a groove 254 between the wing rail section 246 and the crossing nose 242 through which the wheel flanges 256a of rolling stock wheels 256 can pass.

(63) As rolling stock approaches the railway track crossing 240, the movable rail 245 that is in the closed position, and along which it is intended that rolling stock should travel, is gradually loaded by the wheels 256 of the approaching rolling stock and is thereby displaced downwardly from the elevated first position shown in FIGS. 22 and 23 to the second position shown in FIGS. 24 and 25. As the movable rail 245 is displaced downwardly from the elevated first position to the second position, the convex profile section 280 engages the concave profile section 284 as shown in FIGS. 24 and 25 and the movable rail 245 is thus locked in the closed position. As the wheelsets of rolling stock pass through the railway track crossing 240, the load applied to the locked movable rail 245 is intermittently reduced, typically for short periods of a few seconds each. During these short periods, the dampers 276 help to prevent the locked movable rail 245 from springing upwardly from the second position to the first position under the action of the biasing means 274.

(64) After the rolling stock has passed through the railway track crossing 240 and load is no longer applied by the wheels 256 to the locked movable rail 245, the movable rail 245 is biased by the biasing means 274 back to the elevated first position shown in FIGS. 22 and 23. The movement of the movable rail 245 from the second position to the elevated first position is retarded by the dampers 276, thereby ensuring a controlled upward movement. Finally, the controllable drive mechanism is operated to displace the actuator arm 264, and hence the actuating member 262, transversely to a neutral position thereby allowing the displaced movable rail 245 to move from the open position shown in FIGS. 22 to 25 to the closed position shown in FIGS. 20 and 21 to thereby close the groove 254. The railway track crossing 240 is, thus, returned to the neutral state shown in FIGS. 17, 20 and 21. Movement of the displaced movable rail 245 from the open position to the closed position may occur due to the inherent stiffness and natural bend of the movable rail 245 and may be assisted by the biasing means 274. The dampers 276 may also help to retard the movement of the movable rail 245 from the open position to the closed position.

(65) In the unlikely event that the railway track crossing 240 should fail when it is in the neutral state with both of the movable rails 245 in the closed position (for example due to failure of some part of the actuator arrangement 260), rolling stock can still safely pass through the crossing 240 without significantly increasing the derailment risk. In this mode of operation, the wing rail sections 246, and hence the movable rails 245, can be displaced transversely by the wheel flanges 256a of passing rolling stock. The railway track crossing 240 thus acts like a conventional passive swing wing crossing. The dampers 276 also help to prevent the movement of the movable rail 245 from the open position to the closed position after each wheel flange 256a has passed through the groove 254.

(66) Although extremely unlikely, it is possible that the railway track crossing 240 could fail when set for a particular route but that rolling stock may need to pass through the railway track crossing 240 along the other route. For example, the railway track crossing 240 may be set for the straight route as shown in FIG. 18 whereas rolling stock may need to follow the turnout route. As will now be explained, the railway track crossing 240 advantageously allows rolling stock to follow the correct route without derailment, albeit at much reduced speed, even when the crossing 240 is set for an incorrect route.

(67) Referring again to FIG. 18, when rolling stock is executing a trailing-point movement along the turnout route in the converging direction of the rails 244 forming the crossing nose 242, the wheel flanges 256a engage the flared section 258 of the closed wing rail section 246 and push it, and hence the movable rail 245, transversely to the open position. There will, of course, be a gap between the crossing nose 242 and the other wing rail section 246, which has been displaced to the open position by the actuator arrangement 260, that will need to be traversed by the wheels 256. In extreme cases, the wheels 256 may fall to ground or onto a support 243. However, it will be seen from FIG. 27 that the upper surface of the actuating member 262 includes ramp sections 263 at longitudinally opposite ends thereof. These ramp sections 263 help to re-rail the wheels 256 onto the movable rail 245 that has been displaced to the open position by the actuator arrangement 260 and with which the actuating member 262 is, therefore, in contact.

(68) When rolling stock is travelling in the opposite direction and executing a facing-point movement along the turnout route in the diverging direction of the rails 244 forming the crossing nose 242, the wheels 256 derail and ride down the ramp section 263 of the actuating member 262 before the wheel flanges 256a are captured by the crossing nose 242 and re-lifted to follow the appropriate one of the diverging rails 244.

(69) In all of the scenarios described above in which the railway track crossing 240 is incorrectly set to allow the passage of rolling stock along the desired route, it will be understood that the check rails 234 (see FIG. 16) ensure that the rolling stock ultimately follows the correct route.

(70) Although exemplary embodiments have been described in the preceding paragraphs, it should be understood that various modifications may be made to those embodiments without departing from the scope of the appended claims. Thus, the breadth and scope of the claims should not be limited to the above-described exemplary embodiments. Each feature disclosed in the specification, including the claims and drawings, may be replaced by alternative features serving the same, equivalent or similar purposes, unless expressly stated otherwise.

(71) For example, although the embodiment illustrated in FIGS. 1 to 4 has only first and second pairs of stock rails 12, 14 which enable the points arrangement 10 to select between first and second routes through the railway track junction, further pairs of stock rails could be provided with which the switch rails 16 can cooperate thereby enabling more than two routes to be selected.

(72) Although three transversely-spaced recesses 132 are shown in the illustrated embodiments of the points operating apparatus 122, 1122 described with reference to FIGS. 5 to 15, it will be understood that this is illustrative only and that any suitable number of recesses 132 can be provided. In practice, it will be sufficient to provide one recess 132 per route. This means that if the points arrangement 110 comprises only two pairs of stock rails 112, 114 representing first and second routes, only two transversely-spaced recesses 132 will be needed because the switch rails 116 will only be required to move between two positions, namely a first position to select the first route and a second position to select the second route.

(73) In the points operating apparatus 1122 described with reference to FIGS. 14 and 15, the rack gear 164 is arranged below the pinion gears 162, 166a, 166b, with the teeth of the rack gear 164 projecting upwardly. The rack gear 164 could instead be arranged above the pinion gears 162, 166a, 166b, with the teeth of the rack gear 164 projecting downwardly.

(74) Unless the context clearly requires otherwise, throughout the description and the claims, the words comprise, comprising, and the like, are to be construed in an inclusive as opposed to an exclusive or exhaustive sense; that is to say, in the sense of including, but not limited to.

(75) Any combination of the above-described features in all possible variations thereof is encompassed by the present invention unless otherwise indicated herein or otherwise clearly contradicted by context.