GB2417510A

GB2417510A - Vehicle guiding system switch

Info

Publication number: GB2417510A
Application number: GB0419304A
Authority: GB
Inventors: Andrew Raymond Foan
Original assignee: Balfour Beatty PLC
Current assignee: Balfour Beatty PLC
Priority date: 2004-08-31
Filing date: 2004-08-31
Publication date: 2006-03-01
Anticipated expiration: 2024-08-31
Also published as: TW200619468A; WO2006024828A1; GB2417510B; GB0419304D0; TWI349061B

Abstract

The switch 11 connects a primary grooved guide track to two secondary grooved guide tracks and comprises a number of mounting brackets 19, two guiding bars 33, 35, and two switchblades 41, 43. The mounting brackets include a flat base 21 and angled uprights 23, 25 defining mounting surfaces 29, 31. Guiding surfaces 37, 39 of the guiding bars are aligned at a first end of the switch with the opposing guiding surfaces of the primary grooved guide track. They are aligned at a second end of the switch with the outer guiding surfaces of the two secondary grooved guide tracks. The two switchblades are of unequal length and are positioned to slide across switching surface 27 of the mounting brackets between the guiding bars 33, 35. The switchblades have an inverted T-shaped section and provide a guiding surface 45, 47 for the guiding rollers of vehicles. The guiding bars may additionally be adjusted/aligned by mounting one or more shims 49 of differing widths.

Description

Switch This invention relates to a switch for a vehicle guiding system.

In particular, this invention relates to a switch for a vehicle guiding system in which vehicles have a central guiding roller engaged in a grooved guide track.

Vehicle guiding systems in which a vehicle is guided by a grooved guide track are well known. The groove may be defined by a pair of parallel rails mounted on a runway. In this case, the parallel rails are separated by a small distance to provide opposing guiding surfaces. Alternatively, the opposing guiding surfaces may be provided by a groove formed directly in a single rail mounted on the runway. In either arrangement, a central guiding roller depends from the underside of the vehicles and engages between the opposing guiding surfaces of the groove. The wheels of the vehicles bear down on the runway on either side of the groove and are driven to provide traction, and the central guiding roller moves between the opposing guiding surfaces to provide directional control.

Conventional railway switches are not well suited to use in vehicle guiding systems because the switchblades are heavy, and considerable effort is required to move them.

US4032295 discloses a switch adapted for use in a vehicle guiding system.

This switch comprises a fixed subassembly connecting one primary grooved guide track at a first end to two secondary grooved guide tracks at a second end. The fixed subassembly defines the opposing guiding surfaces of the one primary grooved guide track at the first end, and the outer guiding surfaces only of the two secondary grooved guide tracks at the second end. Two movable switchblades secured at their heel ends provide the inner guiding surfaces of the two secondary grooved guide tracks at the second end. The toe end of the switchblades bear against each other, and the switchblades pivot between respective positions in which the one primary grooved guide track at the first end is connected to either of the two secondary grooved guide tracks at the second end. The fixed subassembly of the switch is cast as a single item, and separate moulds are required for different switch geometries. The switch of US4032295 is consequently costly and time consuming to implement.

US5207401 discloses an improved switch for use in a vehicle guiding system fabricated from a number of separate components. Figure 1 shows a cross section through the switch 1. The fabricated arrangement of the switch avoids the requirement for a cast subassembly, which is replaced by two diverging conventional stock rails 3, 5 secured to an end plates 7 at either end of the switch. Although the cost and time taken for implementation of the switch are reduced, the substitution of conventional stock rails for the fixed subassembly of US4032295 introduces a number of drawbacks, both in manufacture and operation of the switch.

For example, the use of conventional stock rails requires that a large amount of material be removed from the cross section, so that the switchblades 9 have sufficient space to move. Out of a rail weighing approximately 38kg/m, one third to one half of the material may be wasted.

According to the invention, there is provided a vehicle guiding system switch for connecting one primary grooved guide track at a first end of the switch to two secondary grooved guide tracks at a second end of the switch, the grooved guide tracks being defined by opposing guiding surfaces, the switch comprising: a plurality of mounting brackets spaced along the switch, the mounting brackets each having a laterally extending base and uprights extending from the base; two non-parallel guiding bars each attached to respective uprights of the mounting brackets and each providing a guiding surface, the guiding surfaces of the guiding bars being aligned at the first end of the switch with the opposing guiding surfaces of the one primary grooved guide track, the guiding surfaces of the guiding bars being aligned at the second end of the switch with the outer guiding surfaces of the two secondary grooved guide tracks; and two movable switchblades positioned to slide on the base of the mounting brackets between the guiding bars and each providing a guiding surface, heel ends of the switch blades being attached to a mounting bracket at the second end of the switch so that the guiding surfaces of the switchblades are aligned with the inner guiding surfaces of the two secondary grooved guide tracks, toe ends of the switchblades bearing against each other and being movable between first and second positions in which the one primary grooved guide track at the first end of the switch is respectively connected to the two secondary grooved guide tracks at the second end of the switch, wherein the guiding bars are attached to the uprights of the mounting brackets in spaced relationship with the bases of the mounting brackets.

Essentially, the invention recognises the fact that, in contrast to conventional railway tracks, the vertical load on the grooved guide track of a vehicle guiding system is minimal. The invention thus provides a switch arrangement in which guiding surfaces are provided by bars vertically spaced from the bases of mounting brackets, rather than by a cast subassembly or by conventional stock rails. By attaching the guiding bars in spaced relationship with the bases of the mounting brackets, the need for individual castings or for significant material removal is avoided, while still providing ample room for movement of the switchblades.

Compared to prior art systems, the guiding surfaces may be easily removed and reattached or replaced for maintenance purposes simply by removing the guiding bars.

In a preferred embodiment, the guiding bars have a substantially rectangular cross-section having two substantially parallel major surfaces and two substantially parallel minor surfaces. Rectangular guiding bars provide improved lateral restraint to the guiding roller of vehicles, especially if they weigh at least 25kg/m.

The guiding surface of the guiding bars is preferably provided by a first one of the major surfaces, and the guiding bars are preferably attached to the uprights of the support brackets by a second one of the major surfaces. This optimal arrangement provides large guiding and attachment surfaces, good lateral restraint, and ample room for movement of the switchblades.

The guiding bars may be further attached to the uprights of the support brackets by a part of a first one of the minor surfaces of the guiding bars. This surface mounts to a substantially horizontal flange formed in the uprights. In this way the guiding bars can also bear a significant vertical load without experiencing excessive shear forces.

The guiding bars are preferably attached to the uprights of the mounting brackets by removable fasteners, such as threaded bolts to facilitate easy removal and/or replacement of the guiding bars. Such attachment methods also eliminate the need for welding, and thus reduce the risk of fatigue failure in service.

An angle between the base of the support bracket and the guiding surface of the guiding bars may be in the range 50 to 88 , preferably 60 to 85 , and most preferably 65 to 80 . Guiding surfaces that are angled in this way provide improved alignment with the switchblades.

The guiding surface of the guiding bars may have a width in the range 50mm to 100mm, preferably 60 to 90mm, and most preferably 70 to 80mm. The vertical distance between the guiding bars and the bases of the mounting brackets may be at least 25mm, preferably 35mm, and most preferably 40mm. The space between the guiding bars and the bases of the mounting brackets may be in the range 30mm to 60mm. The minor surfaces of the guiding bars may have a width in the range 20mm to 60mm, preferably 30 to 50mm, and most preferably to 45mm. Such dimensions provide for a sufficient guiding surface, with ample room for movement of the switchblades.

A lateral distance between uprights, measured at the base of each mounting bracket may be at least 50mm, preferably 60mm, and most preferably 70mm more than the maximum lateral distance between the opposing guiding surfaces of the guiding bars.

The switch preferably comprises more than two mounting brackets, and most preferably at least five mounting brackets. The mounting brackets are preferably spaced at regular intervals along the length of the switch. This arrangement helps to maintain the correct shape of the guiding bars, and thus ensure correct clearance between the guiding surfaces, especially at the sliding interface between the guiding bars and the switchblades.

At least one shim of any suitable thickness may be mounted between uprights of the mounting brackets and the guide bars to provide for adjustability or alignment of the guiding bars.

In a preferred embodiment, a number of the mounting brackets further comprise switchblade stops for restraining lateral movement of the switchblades. The switchblade stops are preferably located between the uprights of the mounting brackets.

According to another aspect of the invention, there is provided a method of adjusting or aligning the vehicle guiding system switch described above, the method comprising mounting one or more shims between the uprights of a mounting bracket and the guide bars attached to the uprights. Different sized shims may be provided to allow for different alignments.

A preferred embodiment of the invention will now be described, purely by way of example, with reference to the following drawings in which: Figure 1 is a cross sectional view of a known vehicle guiding system switch; Figure 2 is a plan view of a vehicle guiding system switch according to the invention; and Figure 3 is a cross sectional of the switch shown in Figure 2, taken across the line A-A.

The invention provides an improved vehicle guiding system switch for connecting one primary grooved guide track at a first end of the switch to two secondary grooved guide tracks at a second end of the switch. Figures 2 and 3 show a preferred embodiment of the invention, and are not drawn to scale.

Referring to Figures 2 and 3, the switch 11 connects one primary grooved guide track 13 at a first end of the switch 11 to two secondary grooved guide tracks 15, 17 at a second end of the switch 11. Each of the grooved guide tracks 13, 15, 17 are defined by guiding surfaces that substantially oppose each other.

The switch 11 comprises a number of mounting brackets 19, two guiding bars 33, 35, and two switchblades 41,43.

The mounting brackets 19 are spaced along the length of the switch 11. The mounting brackets 19 are made of cast iron and each include a flat base 21 extending in a lateral direction, and two uprights 23, 25 extending upwardly from the base 21. The two uprights 23, 25 and the base 21 define a switching surface 27. The uprights 23, 25 extend upwardly at an angle of approximately 75 to the switching surface 27, and to an extent of 120mm. The length of the mounting brackets 19 varies along the length of the switch 11, and the width of the mounting brackets 19, including the uprights 23, 25, is 100mm. The opposing surfaces of the uprights 23, 25 of each mounting bracket 19 define mounting surfaces 29, 31.

The two guiding bars 33, 35 are made of rolled steel and have a rectangular cross section measuring 40mm x 75mm. A major surface of each of the guiding bars 33, 35 is laterally bolted to the mounting surface 29, 31 of an uprights 23, 25 of each mounting bracket 19. The guiding bars are mounted so that the are spaced from the bases 21 of the mounting brackets 19 by a minimum of 50mm in a vertical direction. The guiding bars 33, 35 also stand proud of the uprights 23, 25 in a lateral direction by 35mm. The guiding bars 33, 35 are each mounted so that the uprights 23, 25 provide support for lateral and vertical loads.

The other major surface of each guiding bar 33, 35 provides a guiding surface 37, 39. The guiding surfaces 37, 39 are at an angle of approximately 75 to the switching surface 27.

The guiding surfaces 37, 39 of the guiding bars 33, 35 are aligned at the first end of the switch 11 with the opposing guiding surfaces of the one primary to grooved guide track 13, and the guiding surfaces 37, 39 of the guiding bars 33, are aligned at the second end of the switch 11 with the outer guiding surfaces of the two secondary grooved guide tracks 15, 17.

The two switchblades 41, 43 are of unequal length and are positioned to slide across the switching surface 27 of the mounting brackets 19, between the guiding bars 33, 35. Each switchblade 41, 43 has a broad base having a width of 60mm to provide stable sliding across the switching surface 27, narrowing to a blade-like section having a width of 12mm and which provides a guiding surface 45, 47 for the guiding rollers of vehicles. The switchblades 41, 43 thus have an inverted "T" shaped section. The heel ends of the switch blades 41, 43 are attached to a mounting bracket 19 at the second end of the switch 11 so that the guiding surfaces 45, 47 of the switchblades 41, 43 are aligned with the inner guiding surfaces of the two secondary grooved guide tracks 15, 17. The toe ends of the switchblades 41, 43 bear against each other and are movable across the switching surface 27 of the mounting brackets 19.

The switch 11 also comprises a number of other components that are required for effective implementation, including spacers, stops and actuators.

The stops of the switch 11 comprise switchblade stops (not shown) for restraining lateral movement of the switchblades 41, 43. The switchblade stops are mounted to the bases 21 of a number of the mounting brackets 19, and are located between the uprights 23, 25.

The form and function of the other components, including the spacers and actuators, will be known to persons skilled in the art, and will not be described further.

In use, the switchblades 41, 43 are moved between first and second positions in which the one primary grooved guide track 13 at the first end of the switch 11 is respectively connected to either of the two secondary grooved guide tracks to 15, 17 at the second end of the switch 11. The switchblades 41, 43 will typically be moved by actuators that will be well known to persons skilled in the art.

In the first position, one of the switchblades 41, 43 abuts the guiding surface of a guiding bar 33. In the second position, one of the switchblades 41, 43 abuts the guiding surface of the other guiding bar 35 (as shown in Figure 3).

The attachment of the guiding bars 33, 35 in a raised position, as shown in Figure 3, provided the maximum amount of lateral space beneath the bars 33, 35 in which the switchblades 41, 43 can move, thus allowing the switchblades 41,43 to be designed with a wide base for good strength and stability.

The use of lateral fasteners to attach the guiding bars 33, 35 to the uprights 23, of the mounting brackets 19 allows for a simple and convenient technique for adjusting and/or aligning the guiding bars 41, 43 of the switch 11.

Specifically, one or more shim 49 of differing widths are mounted between the uprights 23, 25 and the guiding bars 33, 35. Reducing or increasing the number and/or thickness of the shims 49 causes the guiding bars 33, 35 to be laterally displaced relative to the mounting brackets 19. This technique can be used both during the initial installation of the switch 11 and during maintenance of the switch 11 to correct distortions in the guiding bars 33, 35.

Various modifications to the invention will be apparent to persons skilled in the art.

For example, although specific dimensions have been provided in relation to the exemplary embodiment described above, the invention is not limited to these dimensions.

Claims

Claims: 1. A vehicle guiding system switch for connecting one primary

grooved guide track at a first end of the switch to two secondary grooved guide tracks at a second end of the switch, the grooved guide tracks being defined by opposing guiding surfaces, the switch comprising: a plurality of mounting brackets spaced along the switch, the mounting brackets each having a laterally extending base and uprights extending from the base; two non-parallel guiding bars each attached to respective uprights of the mounting brackets and each providing a guiding surface, the guiding surfaces of the guiding bars being aligned at the first end of the switch with the opposing guiding surfaces of the one primary grooved guide track, the guiding surfaces of the guiding bars being aligned at the second end of the switch with the outer guiding surfaces of the two secondary grooved guide tracks; and two movable switchblades positioned to slide on the base of the mounting brackets between the guiding bars and each providing a guiding surface, heel ends of the switch blades being attached to a mounting bracket at the second end of the switch so that the guiding surfaces of the switchblades are aligned with the inner guiding surfaces of the two secondary grooved guide tracks, toe ends of the switchblades bearing against each other and being movable between first and second positions in which the one primary grooved guide track at the first end of the switch is respectively connected to the two secondary grooved guide tracks at the second end of the switch, wherein the guiding bars are attached to the uprights of the mounting brackets in spaced relationship with the bases of the mounting brackets.
2. The switch of claim 1, wherein the guiding bars have a substantially rectangular cross-section having two substantially parallel major surfaces and two substantially parallel minor surfaces.
3. The switch of claim 2, wherein the guiding surface of the guiding bars is provided by a first one of the major surfaces.
4. The switch of claim 2 or 3, wherein the guiding bars are attached to the uprights of the support brackets by a second one of the major surfaces.
5. The switch of claim 4, wherein the guiding bars are further attached to the uprights of the support brackets by a part of a first one of the minor surfaces, the part of the minor surface mating with flanges formed in the uprights of the support brackets.
6. The switch of any preceding claim, wherein the guiding bars are attached to the uprights of the mounting brackets by substantially lateral removable fasteners.
7. The switch of any preceding claim, wherein an angle between the base IS of the support bracket and the guiding surface of the guiding bars is in the range 60 to 85 .
8. The switch of any preceding claim, wherein the guiding surface of the guiding bars has a width in the range 50mm to 100mm.
9. The switch of any preceding claim, wherein the space between the guiding bars and the bases of the mounting brackets is at least 25mm.
10. The switch of claim 9, wherein the space between the guiding bars and the bases of the mounting brackets is in the range 30mm to 60mm.
11. The switch of any one of claims 2 to 5, wherein the minor surfaces of the guiding bars have a width in the range 20mm to 60mm.
12. The switch of any preceding claim, wherein a distance between uprights at the base of each mounting bracket is at least 50mm more than the maximum distance between opposing guiding surfaces of the guiding bars adjacent that mounting bracket.
13. The switch of any preceding claim, wherein the guiding bars are made of steel.
14. The switch of any preceding claim, wherein the mounting brackets are made of cast iron.

15. The switch of any preceding claim, comprising more than two mounting brackets.
15. The switch of any preceding claim, further comprising at least one shim mounted between an upright of a mounting bracket and a guide bar attached to the upright.
16. The switch of any preceding claim, wherein a number of the mounting brackets further comprise switchblade stops for restraining lateral movement of the switchblades.
17. A method of adjusting or aligning a vehicle guiding system switch, the switch being for connecting one grooved guide track at a first end of the switch to two grooved guide tracks at a second end of the switch, the grooved guide tracks being defined by opposing guiding surfaces, the switch comprising: a plurality of mounting brackets spaced along the switch, the mounting brackets each having a laterally extending base and uprights extending from the base; two non-parallel guiding bars each attached to respective uprights of the mounting brackets and each providing a guiding surface, the guiding surfaces of the guiding bars being aligned at the first end of the switch with the opposing guiding surfaces of the one grooved guide track, the guiding surfaces of the guiding bars being aligned at the second end of the switch with the outer guiding surfaces of the two grooved guide tracks; and two movable switchblades positioned to slide on the base of the mounting brackets between the guiding bars and each providing a guiding surface, heel ends of the switch blades being attached to a mounting bracket at the second end of the switch so that the guiding surfaces of the switchblades are aligned with the inner guiding surfaces of the two grooved guide tracks, toe ends of the switchblades bearing against each other and being movable between first and second positions in which the one grooved guide track at the first end of the switch is respectively connected to the two grooved guide tracks at the second end of the switch, wherein the guiding bars are attached to the uprights of the mounting brackets in spaced relationship with the bases of the mounting brackets, the method comprising mounting one or more shims between the uprights of a mounting bracket and the respective guide bars attached to the uprights.