EP0040533B1

EP0040533B1 - Railway turnouts

Info

Publication number: EP0040533B1
Application number: EP81302188A
Authority: EP
Inventors: Imre Csontos
Original assignee: Individual
Current assignee: Individual
Priority date: 1980-05-19
Filing date: 1981-05-18
Publication date: 1985-04-17
Also published as: EP0040533A3; AU542565B2; AU557958B2; AU3594584A; EP0040533A2; DE3169946D1; AU7066681A

Description

This invention relates to. railway turnouts. In prior art turnouts the point of the semi-curved switch blade is merely switched to a position closely adjacent the stock rail when in the turnout position. The point is machined down to a narrow taper to allow the flange of the wheel to enter the turnout. It will be appreciated that the point cannot be machined down completely as a certain amount of metal has to remain to provide the strength required to absorb the lateral thrust applied to the point. The remaining metal results in a ridge standing proud of the stock rail when the switch blade is in the turnout position, and it will be evident that this ridge will wear down quite rapidly.
Furthermore, in a railway tournouts, the wing rails are normally laid with a constant elevation while the point rail nose is provided with a reverse slope from a point lower than the plane of the wing rail. The car wheels are coned and, in running over the crossing, encounter a position on the wing rail where the wing rail deviates from the direction of travel of the wheel or gauge line at the throat of the flangeway of the crossing rail.
The wheel drops as the point of contact between the rail and the wheel moves outwardly on the conical wheel tread and, in dropping, it encounters the nose, rides up the reverse slope and proceeds at the proper elevation, hammering the nose in the process.
It is one object of this invention to minimise this problem by providing a raised wing rail.
It is a further object of the invention to provide a turnout which reduces the first mentioned problem by providing a guard rail arrangement.
In this specification the term "first stock rail" will be used to denote the stock rail directly adjacent the curved switch blade, i.e. the main rail, while the term "second stock rail" will denote the stock rail directly adjacent the standard straight blade, i.e. the siding rail.
The preamble of claim 1 which is set forth in the following paragraph is disclosed in FR A403580(1) (Wyler et al).
According to one aspect of the invention there is provided a railway turnout including a curved switch blade movably located adjacent a main line stock rail, a standard switch blade movably located adjacent a siding rail, the turnout including a guard rail which is located adjacent the siding stock rail and adapted to draw the wheel flanges of the wheels of a car, moving through the turnout, away from the gauge line of the main line stock rail, the curved switch blade being longer than the standard switch blade. The main line rail is formed with a recess adapted to receive the point of the curved switch blade and the recess in the main line stock rail is formed adjacent a joint between two adjacent main line stock rails, which joint falls within the zone on the main line rail straddled by the guard rail.
A turnout constructed in this way provides extended protection for, and therefore a very greatly reduced rate of wear of, the side of said joint between the two adjacent main line stock rails that faces the car wheel flanges.
The invention includes a method of making the above turnout and comprises the steps defined in claim 2.
Railway frogs using raised wing rails have been proposed by Keough in US patent no. 1,389,144 and Carruthers, US patent no. 2,012,807. Keough suggest that the wing rail be raised or that the point be lowered to prevent the wheel striking the point and breaking it down. The raised wing rail is sketchily described, but it appears merely to provide a ramp to lift the car wheels over the point of the nose, the frog depending more on a narrow flangeway to force the wheel tread on to the nose tread surface. Keough also proposes a deep wide throat which will tend to offset the advantage gained by the raised wing rail.
Carruthers uses a frog in which the point is inclined above the plane of the stock rail tread surfaces, as are the wing rails. The height above the plane of the stock rails is determined by the expected ultimate displacement of surface metal as a result of cold flow thereof in an endeavourto obtain, once the metal has stabilised, the proper elevation on the point rail in particular. The tread surface of the wing rails are horizontal with the result that a car wheel, in transferring from the wing rail to the nose, will place a substantially point load on the inner edge of the wing rail, notwithstanding that the wing rail is raised.
DE-U-1 989 037(3) describes a turnout in which the normal inclination on the head of the rails in a rail system is continued throughout the turnout. The heads of rails in rail systems are very often provided with a transverse inclination corresponding to the incline on the conical wheels of the rolling stock. This is done to minimise line contact between the coned wheels and the edges of the prior art level rail heads. In many parts of the world, an arbitrary crossfall of 1:20 is used to match the 1:20 cone angle of the wheels and DE-U-1 989 037(3) merely provides for continuity of the track condition throughout the turnout. To implement the present invention in practice, a statistical exercise is undertaken by actually measuring a number of worn wheels of cars using the rail system so that the profile of an "average worn wheel" can be found. This profile is then projected transversely across the slope of the wing rail inserts. It will be appreciated that this transverse slope or crossfall differs from the arbitrary slope or crossfall originally given to the system rails since this latter crossfall corresponds to the profile of a new wheel and not to that of a worn wheel.
In addition to the crossfall mentioned above, the profile obtained by finding the shape of the average worn wheel is also projected longitudinally along the length of the wing rails rising from a low point adjacent the throat of the crossing to a high point at the heels of the wing rails. This longitudinal ramping is not shown in DE-U-1 989 037(3) and a study of its drawings and sections C-C, D-D and E-E in particular (Figures 4, 5 and 6) shows that the chairs (3) on which the wing rails are mounted have a constant thickness throughout, which indicates a constant elevation of the rail head.
A second aspect of the present invention accordingly provides a railway turnout comprising two wing rails and a point which includes a nose, the running surface of the point being substantially co-planar with the surfaces of the rails in the rest of the turnout, characterised in that the wing rails are provided with tread surfaces inclined upwardly above the plane of the running surfaces, the incline of the wing rails extending longitudinally along the wing rails toward the heels thereof and commencing at a point corresponding to the point of deviation from the gauge line of the wing rail, the tread surfaces of the wing rails being sloped, in cross section, from the edge adjacent the gauge line, at an angle corresponding to the shape of the average worn car wheel, the angles of the incline and the slope being dependent on the taper of the wheels and on the angle of deflection of the turnout. The preamble of claim 3, which has just been recited, is disclosed in DE-U-1 989 037(3). Advantageously, the wing rail inclination is provided by a tread surface insert which, in cross section, is provided with the slope described above and which is inclined from the toe to the heel of the crossing. The cross-section shape of the wing rail may be altered by means of additive welding. Only the edge of the wing rail facing the point need be altered.
The inserts are preferably of steel hardened to tool steel hardness.
The nose is preferably carried on a frog comprising a main filler adapted to be bolted or otherwise secured between the vertical webs and base flanges of the wing rails, and a point filler comprising the point and a base, the main filler being formed with a recess adapted to receive the base of the point filler and the point being shaped to abut the severed point rails in use.
In the drawings: Figure 1 is a diagrammatic plan view of a prior art turnout showing the various parts thereof as they relate to the crossing:

Figure 2 is a plan view of the crossing of the turnout of the invention;
Figure 3 is a section on line III-III in Figure 2; and
Figure 4 is a section on line IV-IV in Figure 1.

The invention is further described with reference to the drawings related to the guard rail and switch blades in which:

Figure 5 is a plan view of a prior art right hand turnout showing the component parts thereof as they relate to the switch blades:
Figure 6 is an enlarged plan view of a left hand turnout according to the invention; and
Figure 7 is a section taken at line VII-VII in Figure 6.

The prior art turnout 10 shown in Figure 1 comprises a crossing 24 consisting of a left hand wing rail 12, a right hand wing rail 14, a point or long point rail 16, a splice rail or short point rail 18 and two guard rails 20, 22. The wing rails 12, 14 define a throat 26 for two flangeways 28, 30. The short point rail 18 is slanted and abuts the long point rail 16 which is provided with the point 32. The toes 34, 36 of the wing rails 12, 14 abut the siding rail 38 and the main line rail 40 while the heels 42 are at the runout ends of the wing rail.
The crossing of the invention (denoted generally by the reference 124) is shown in more detail in Figure 2. The one gauge line 126, shown in chain line, is an imaginary line indicating the path followed by the wheel flange of a car wheel traversing the crossing 124 from left to right. The problem associated with the prior art is well illustrated by following the gauge line 126 from the bottom of the drawing to the top. As the wheel negotiates the gap (B-C), the entrance to the flangeway 128, the wing rail 112, and therefore the support beneath the wheel, is deviating from the gauge line 126 at a given angle (depending on the angle of deflection of the turnout) and, due to the coning of the wheels, the wheel comes down in elevation. At this point the wheel meets the nose 132, changes direction, on the reverse slope of the prior art point, and continues on its way. The point 133, which is, by nature of its function, a narrowed tapered piece of metal, is rapidly worn away by the repeated hammer blows.
It is proposed to arrange the wing rails 112, 114, so that they are inclined upwardly from their point of departure from the gauge line 126. This is done by the provision of wing rail inserts 144, 146 which are inclined from the toe to the heel of the wing rails 112, 114 as can be seen from the elevation in Figure 3. In this manner the drop in elevation of the wheel is countered by a corresponding raising of the wheel by the wing rail inserts 142, 146, so that the tyre of the wheel is on a plane with the tread surface of the point 133 at the point of contact. It is anticipated that the lessening of the impact achieved by the raising of the wing rails will prolong the life of the point 133 and nose 132 substantially.
The raising of the wing rail can be clearly seen in Figure 3 where the tread surface of the wing rail 112 is shown to depart from the plane of the other rails in the turnout by an angle 0, which will, of course, vary for every turnout angle as well as the angle of taper of the wheel, but is merely a matter of calculation.
The rounded edges of the rail heads reduce the horizontal tread surface of the rail in the crossing 124, the effective point of first contact between the tread surface of the rail head and the tyre being inwardly of the rail edge and conversely, of the gauge line 126. This means that the contact point between the wing rail 112 and the wheel starts moving away from the flange before the point B and in fact the contact points start deviating at a point A as the wheels traverse the crossing 124. By providing the tread surfaces of the inserts 144,146, with a rectangular profile or a sharp inner edge, as shown in Figure 4, the distance A-B is added to the running surface of the rail. In a 1:9 turnout the added support length is approximately 100 mm. The same distance, by the same token, is added at the run-off edge of the insert (distance X-Z).
The point 133 is also rectangularly profiled in this manner. The nose 132, is standard, the tapered sides being necessary to prevent a derailment. However, once a point is reached where the wheel is in flangeway, the sides of the nose are angled towards the vertical crowned rectangular profile as shown in Figure 4, thereby adding running surface to the rail in the same manner as is achieved by the profiling of the wing rails 112, 114.
The inserts 144, 146 are keyed and material is removed from the wing rail heads to accept the inserts, the recesses so formed being provided with grooves 148 to accept the keys 150 on the inserts whereby the latter are located on the wing rails and secured by means of bolts.
The inserts 144, 146, instead of having horizontal tread surfaces are sloped upwardly from the inner edges of the wing rails 112 and 114 so that, instead of a point contact between the coned wheel and rail, a line of contact is established. The wheel rim is therefore supported on the whole of the rim surface remaining above the wing rail instead of merely the edge of the wing rail. The slope of the insert is, of course, commensurate with the profile of an average worn wheel.
The point 133 is carried on a frog 152 which may be cast or machined from a block. The frog 152 comprises a base which is carried on the base flanges of the wing rails and abuts the vertical webs. The frog is tranversely bolted through the webs of the wing rails and formed with a recess into which the point insert 133, which is provided with a base 154, is adapted to fit. The point insert base is secured into the recess by means of Allen (Trade Mark) screws.
The heel of the frog 152 and the point insert 133 is slanted and abuts the ends of the long and short point rails 116 and 118 which are slanted to accept the frog and point insert. Once inserted and bolted the frog 152 is therefore securely located in between the wing rails.
Replacement of the wing rail and point inserts is merely a matter of the removal and replacement of a set of bolts and screws, the slanted ends and keys of the wing rail inserts and the definitive shape of the point insert recess in the frog 152 as well as the slanted heel of the point insert, ensuring the accurate location of the various elements.
In Figure 5 a railway turnout 210 is shown to comprise a first stock rail 212, a second stock rail 214, a curved switch blade 218 and a standard switch blade 216. The operation of the turnout 210 is well known, the movement of the curved switch blade 218 away from the stock rail 212 causing a train to proceed along the main line rail 213, 213a and the removal of the standard switch blade 216 from the second stock rail 214 along with the positioning of the curved switch blade 218 adjacent the first stock rail 212, causing the train to turn out onto the siding rails 215, 215a. The point of the curved switch blade 218, denoted by the number 220, bears the burden of initiating the deflection of the wheels, and understandably, is worn away very rapidly.
In Figure 6 the turnout of the first aspect of the invention is shown, comprising a first stock rail 302 which is formed with a recess 304 therein to receive the point 306 of the curved switch blade 308. A guard rail 310 is provided next to the second stock rail 312. The guard rail 310 is attached to the sleepers in the normal manner and spaced from the stock rail 312 by means of standard cast iron spacer blocks 314. Greasing of the fish plates may present a problem due to the provision of the guard rail 310, but this can be overcome by HUCK (Trade Mark) bolting of the fish plates in the joint.
When the turnout is in the turnout position, the point 306 of the curved switch blade 308 nestles within the recess 304 where it is out of the way of wheel flanges moving through the turnout 300 from either the trailing - (arrow 318) or facing direction (arrow 320). The guard rail 310 serves as an additional means of protecting the point 306 by drawing the flanges of the wheels away from the point 306.
It will be appreciated that a recessed stock rail 302 as used here, necessitates the use of the guard rail 310 with the turnout in the open position, that is when a train passing through the turnout 310 goes straight. A train moving out of the turnout in the trailing direction 318 stands the chance of following the recessed gauge line (the inside line of the track), and hitting the end of the recess 306 with its wheel flanges with derailment as the possible result. The guard rail 310 will prevent the wheels from tracking along the recessed gauge line.
It is self evident that the proposed curved switch blade 306 need not be cut down to as narrow a point as the prior art switch blades with the result that the point is stronger as it has a greater mass of material.
The point of the shortened standard switch blade 322 need not be received in a corresponding recess in the second stock rail 312. When the point of the standard switch blade 322 is laid against the stock rail 312 the car wheels tend to continue in a straight line upon entering the turnout 310. However, the point 321 lies behind the gauge line, the second stock rail 312 being bent away from the straight line path that the wheels tend to follow. The point 321 lies behind the point 322 when they pass it.
The manufacture of the proposed turnout requires less milling operations than the prior art turnouts where up to four different operations or settings on the cutting or milling machine were required. In the section in Figure 7 it can be seen that the material of the stock rail 302 is taken off by plane milling or cutting to provide the recess 304 while the mating face 305 of the switch blade 306 is also plane cut to fit complementally against the switch blade 306 and the remainder provides, in conjunction with the stock rail 302, a running surface equal in width to the rest of the rail 302. The plane cutting operations are obviously less expensive than the intricate milling operations required before.

Claims

1. A railway turnout including a curved switch blade (308) movably located adjacent a main line stock rail (302), a standard switch blade (322) movably located adjacent a siding stock rail (312), the turnout including a guard rail (310) which is located adjacent the siding stock rail (312) and adapted to draw the wheel flanges of the wheels of a car, moving through the turnout, away from the gauge line of the main line stock rail (302), the curved switch blade (308) being longer than the standard switch blade (322), characterised in that the main line rail (302) is formed with a recess (304) adapted to receive the point (306) of the curved switch blade (308), and the recess (304) in the main line stock rail (302) is formed adjacent a joint between two adjacent main line stock rails, which joint falls within the zone on the main line rail straddled by the guard rail (310).

2. A method of manufacturing a turnout according to claim 1 comprising the steps of forming a recess (304) adapted to receive the point (306) of the curved switch blade (308) in the main line stock rail (302) of the turnout and arranging the point (306) of the curved switch blade (308) to be received in the recess (304) when the curved switch blade (308) is in the turnout position, characterised in that the recess (304) is formed by cutting the base flanges and head of the main line stock rail (302) simultaneously in a single plane cutting operation, the mating face (305) of the curved switch blade (308) being plane cut to fit complementally in the recess (304) in the the main line rail (302).

3. A railway turnout comprising two wing rails (112,114) and a point (113), which includes a nose (132), the running surface of the point (133) being substantially co-planar with the running surfaces of the rails in the rest of the turnout, characterised in that the wing rails (112, 114) are provided with tread surfaces inclined upwardly above the plane of the running surfaces, the incline of the wing rails (112,114) extending longitudinally along the wing rails toward the heels thereof and commencing at a point corresponding to the point of deviation from the gauge line (126) of the wing rail (114), the tread surfaces of the wing rails being sloped, in cross section (Figure 4), from the edge adjacent the gauge line (126), at an angle corresponding to the shape of the average worn car wheel, the angles of the incline and the slope being dependent on the taper of the wheels and on the angle of deflection of the turnout.

4. A turnout according to claim 3, characterised in that the inclination on the wing rails (112, 114) is obtained by the provision of tread surface inserts (144, 146) which, in cross section, are provided with corresponding slopes arranged, in use, to extend upwardly from the edges adjacent the gauge lines (126) to the outer edges of the inserts (144,146) at an angle corresponding to the shape of the average worn car wheel, the inserts (144, 146) being adapted for location in recesses (148) formed in the heads of the wing rails (112, 114).

5. A turnout according to claim 4 characterised in that the inserts (144, 146) are manufactured from steel hardened to tool steel hardness.

6. A turnout according to any one of claims 3, 4 or 5 which includes a frog (152) comprising a main filler block which is adapted to be bolted between the vertical webs and base flanges of the wing rails (112, 114) and a point filler block adapted for location on the frog (152), characterised in that the point (133) is included in a point filler block comprising the point (133) and a base (154), the main filler block and the point (133) being shaped to abut the severed point rails, in use.