US20020073875A1

US20020073875A1 - Oblique expansion gap for between consecutive sections of railway tracks

Info

Publication number: US20020073875A1
Application number: US09/967,830
Authority: US
Inventors: Chewa Liew
Original assignee: Individual
Current assignee: Individual
Priority date: 2000-09-26
Filing date: 2001-10-01
Publication date: 2002-06-20

Abstract

An improved expansion gap designed to permit expansion tolerances between consecutive rail end sections which is comprised of corresponding oblique end cuts for the stock rail head with the combination of conventional squared-end cuts for both the web portion and the stock rail foot of the adjacent rail section ends; having connecting and fastening means so arranged as to produce a no-gap resultant effect, therefore achieving a continuous and uninterrupted surface on the rail end sections to provide for the smooth transfer of the wheels of railway vehicles across these rail end sections, while allowing for expansion tolerances yet able to greatly reduce/overcome the impact and pounding of the rolling wheels. The practical angles of obliqueness for the stock rail head being between 10 degrees to 60 degrees and a 30-degree of obliqueness is considered very suitable.

Description

TECHNICAL FIELD

This innovation relates to an orientation of expansion gap that must be allowed for between consecutive sections of metal railway tracks to cope with expansion and contraction due to rolling frictional heat, cold and hot day temperature changes.

BACKGROUND ART

Expansion gaps that are orientated as conventional squared-end gap are known and have been allowed for between consecutive rail sections of metal railway tracks for the expected expansion. However these said expansion gaps contribute to the reduction of the quality of train-ride and passenger comfort as when the wheels of train coaches roll and cross over such expansion gaps, which due to impact and pounding at said squared-end sections forming the expansion gaps generate much noise and vibration that is disturbing to the enviroment of people and residence.

The said impact and pounding happens when the wheels leaving the immediate rail section end thereat drops below the normal track level into the conventional squared-end expansion gap through continuing to engage the consecutive rail section end. As such there is increased wear of tracks at these squared-end sections forming the expansion gap as well as increased damage to their base-foundations and to the rolling wheels.

Many proposals and much effort have been used to overcome or lessen the aforesaid disadvantages by employing inventions of expansion joints, sliding joints or the like for part of a railway track as disclosed in U.S. Pat. Nos. 3,008,644—November 1961—Wagner, 4,171,774—October 1979—Deslauriers, 4,785,994—November 1988—Crone et al, 5,590,833—January 1997—Benenowski et al.

The above-mentioned patented inventions have been able to do away with the standard squared-end expansion gap together with many of its inherent aforesaid disadvantages; and may only be applicable to all-new railway track construction. However old rail track lines may not quite benefit from these inventions as they probably have quite worm-down height differences between the invented new parts i.e. stock rail sections etc.

It is also noted that employment of the above-mentioned patented inventions of expansion/sliding joints have many disadvantages because they incur such substantial high cost of fabrication of many parts and of their required precision and the high cost of construction and complex assembly.

Though the said inventions claimed to have achieved constant track gauge at those sliding/expansion joints, it is found to be satisfactory in practice in low speed trains only because slight lateral shift is sometimes detected. Even from drawings and theory and due to the changes/movement to be expected of the joint i.e. the tongue and stock rail, geometry will change accordingly and constant track gauge will be slightly affected.

OBJECTS OF THE INNOVATION

The object of the present innovation provides for an oblique expansion gap that can advantageously produce a no-gap resultant effect therefore achieving a continuous and uninterrupted surface for the smooth rolling of wheels which is easy to be adapted to both all-new construction of railway track lines designed in accordance with the innovation and also for the upgrading of the presently-in-use railway track lines having the conventional squared-end expansion gap of prior art.

The other objects of the present innovation are to advantageously overcome the aforesaid disadvantages such as reduced passenger comfort, noise and vibrations, the impact and pounding at the rail section ends and their increased wear and damages at their base-foundations and to the rolling wheels as known to conventional squared-end expansion gaps. By achieving continuous or uninterrupted railway track surface, smooth transfer of wheels from section to section is attained and therefore the train-ride is smooth and so enhances passenger comfort. Impact and pounding is greatly reduced or overcome and so is the effective reduction of noise and vibrations. Wear and damages to other many components are effectively reduced.

The object of the present innovation provides for a much more simple and very cost effective method of construction applicable to both all-new construction of railway track lines as well as for the upgrading of old railway track lines. The innovation further provides easy achieving of constant track level and constant track gauge; and is rugged, dependable and requires low maintenance.

The above and other objects of the present innovation will become more apparent from the description which follows in which reference is made to the accompanying drawings wherein; [0011]
FIG. 1 shows a perspective view of a conventional squared-end expansion gap ([0012] 16) to prior art and an oblique expansion gap (I 8) in accordance with the innovation.
FIG. 2 shows a plan/top view of the conventional expansion gap ([0013] 16) of prior art.
FIG. 3 shows a side view of FIG. 2. [0014]
FIG. 4 shows a plan/top view of the oblique expansion gap ([0015] 18) in accordance with the innovation.
FIG. 5 shows a side view of FIG. 4.[0016]

DETAILED DESCRIPTION OF THE INNOVATION

FIG. 1 shows a perspective view of a conventional squared-end expansion gap ([0017] 16) according to prior art. The stock rail (10) have squared-end cuts and between the rail sections 42 and 40 is provided an expansion gap (16) having one end face 32 with edge 30) and another end face 36 with edge 34. The two rail sections are connected by fishplates fastening means not shown. Referring to FIG. 3 as wheel (20) roll on the surface (11) of stock rail (10) the tangential point x width (2) of the wheel (20) rest on firm support rolling on normal track level. However as the wheel roll into the expansion gap (16) the tangential point x width (2 a) drops to below track level at (22), and the wheel (20) is supported at 24 and 26 engaging the rail section end edges 34 and 30 thereat generating the impact and pounding of the rail track by the wheel, so creating much noise and vibration. Here is how arises all of the disadvantages aforesaid and known to the conventional squared-end expansion gap (16).
Referring to FIG. 1. [0018]
In accordance with the present innovation, the oblique expansion gap ([0019] 18) disposed on normal sleepers is broadly comprised of a first rail section end (38) having an oblique-end cut face (56) for the stock rail head (12) and conventional squared-end cut face for both the web portion (13) and the stock rail foot (14), all with a common point centre; a second rail section end (40 a) having a corresponding oblique-end cut face (52) for the stock rail head (12) and corresponding conventional squared-end cut face for both the web portion (13) and for the stock rail foot (14), all with a common point centre. Non-positive fastening means is used for connecting the said first rail section end (38) with second wail section end (40 a). The connection is thereby arranged to provide an oblique-end expansion gap (18) for the consecutive end sections for the stock rail head portion (12) and with combination of conventional squared-end expansion gap (16 a) for both the web portion (13) and the stock rail foot portion (14) as in FIG. 4 and FIG. 5.
The oblique expansion gap ([0020] 18) so arranged as to produce a no-gap resultant effect and therefore achieve a continuous and uninterrupted surface on the rail end sections to provide for the smooth transfer of the wheels of railway vehicles across the rail end sections, while allowing for expansion tolerances yet able to greatly reduce/overcome the impact and pounding of the rolling wheels.
The no-gap resultant effect can be understood by referring to FIG. 4. When wheel ([0021] 20) approach the oblique expansion gap (18) the tangential point x width (2 c) representing the wheel (20) contact on rail section (40 a), while being well support on the rail section (40 a) at 60 already engages the consecutive rail section (38) at 61. Further on at 2 d, the wheel is evenly supported on both the rail sections and at 2 e, the wheel (20) gets more contact at 63 on rail section 38 as the wheel (20) leaves contact at 62 on the rail section 40 a. Therefore it is now apparent that the wheel (20) rolls over the oblique expansion gap (18) designed in accordance with the innovation and do not momentarily fall below normal track level as with the conventional squared-end expansion gap (16).
In accordance with the innovation, upgrading of old rail track is possible wherein the conventional squared-end expansion gap([0022] 16) is welded confining to the stock rail head portion(12) only as shown in the shaded area of FIG. 1 and to leave the gap of the web portion(13) and stock rail foot portion(14) free of welding. Also the other components of fastening means not shown on both sides of the sections at the web portion should be left unchanged
Further the welded surface of the squared-end expansion gap is evenly grind to conform to the surface contour corresponding to that of the adjacent surface of the rail track. Thereafter at the very same centre position of the welded gap is made a new cut gap orientated in an oblique position/angle as shown in FIG. 1 and FIG. 4. Preferably the angles of obliqueness of between 10 to 60 degrees may be used. The preferred description uses a 45-degree of obliqueness ([0023] 45) as a practical application. Other more practical angle of obliqueness namely a 30-degree angle may be determined and standardised by way of mathematical calculations, computer simulations or even by practical l physical testing and observation; data recording and comparison of all related factors.

Claims

1. An expansion gap for part of a railway track capable to provide for the smooth transfer of rolling train wheels with minimum impact and pounding disposed on normal sleepers comprising:

a first rail section end having an oblique-end cut for the stock rail head and conventional squared-end cut for both the web portion and stock rail foot all with a common point centre;

a second rail section end having a corresponding oblique-end cut for the stock rail head and conventional squared-end cut for both the web portion and the stock rail foot all with a common point centre;

non positive fastening means for connecting the said first rail section end with said second rail section end;

the connection arranged to provide an oblique-end expansion gap for the consecutive sections of the stock rail head and combination of conventional squared-end expansion gap for both the web portion and the stock rail foot;

an expansion gap for part of a railway track as defined in the above, the said angle of obliqueness being 10 degrees to 60 degrees;

an expansion gap for part of a railway track as defined in the above, the said angle of obliqueness being 30 degrees;

an expansion gap for part of a railway track as defined in all of the above, being applicable for the upgrading of already-in-use-constructed railway tracks having only squared-end expansion gaps.