Rail joint for expansion between rails with inverted T-shaped base holder

A rail joint for interconnecting two successive rail bars of a railroad track includes longitudinally aligned first and second guide rails. Each of the guide rails has a mounting end adapted to be secured to a respective one of adjacent end portions of the rail bars, a distal end opposite to the mounting end and spaced from the distal end of the other one of the guide rails at an expansible space, and a downwardly and longitudinally extending dovetail projection. A connector is adapted to be fixed on the railroad track and is formed with an upwardly opening and longitudinally extending dovetail groove for receiving fittingly the dovetail projections of the guide rails therein so as to maintain alignment of the guide rails.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to a rail joint, more particularly to a rail joint 
which is used for interconnecting two successive rail bars of a railroad 
track so as to reduce vibration and noise generated by a train when the 
train passes over the rail joint of the railroad track. 
2. Description of the Related Art 
The improvement of this invention is directed to a conventional rail joint 
which is used for interconnecting two successive rail bars of a railroad 
track. 
Referring to FIG. 1, a railroad track 10 includes two rows of successive 
rail bars 11 which are fixed on several transverse sleepers 12 in a known 
manner and which support wheels 20 (only one is shown) of a train thereon. 
Any successive two of the rail bars 11 form an expansible space 13 between 
their adjacent end portions so as to permit thermal expansion of the rail 
bars 11. The successive rail bars 11 are then connected to each other by 
means of a conventional rail joint to ensure alignment of the successive 
rail bars 11 in order to avoid violent vibration of the successive rail 
bars 11 when the wheels 20 of the train pass over the expansible space 13, 
thereby minimizing unsteady movement of the train. The conventional rail 
joint usually includes a pair of fishplates 14 (only one is shown) which 
are mounted securely to two opposite side walls of the successive rail 
bars 11 by means of bolts 15. However, owing to the frequent thermal 
expansion and contraction of the successive rail bars 11, the bolts 15 are 
easily loosened from the successive rail bars 11 to result in untimely 
removal of the fishplates 14 from the successive rail bars 11. Thus, the 
expansible spaces 13 in any two adjacent end portions of the rail bars 11 
cannot be maintained at equal distances. This results in violent vibration 
of the train when the wheels of the train pass over the unequal expansible 
spaces 13. Accordingly, it is necessary to inspect frequently the 
combination of the bolts 15 and the successive rail bars 11 to ensure that 
the fishplates 14 remain mounted securely to the successive rail bars 11. 
In addition, the adjacent end portions of the successive rail bars 11 are 
respectively provided with vertical and flat end surfaces. As the train 
moves along the railroad track 10, each wheel 20 of the train is 
transferred from the adjacent end portion of one of the rail bars 11 onto 
the adjacent end portion of the other one of the rail bars 11 within a 
very short time such that the adjacent end portion of the other one of the 
rail bars 11 has to burden instantaneously the weight carried by the wheel 
20. As a result, the impact of the wheel 20 with the other one of the rail 
bars 11 during the transfer process may result in violent vibration of the 
train and in a very loud noise. 
In order to overcome the above described drawback, an improved railroad 
track has been disclosed in U.S. Pat. No. 207,792. As disclosed, each of 
opposed end portions of each of aligned rail bars of the railroad track 
has an inclined end face that is parallel to an inclined end face of an 
adjacent one of the rail bars. The inclined end faces are oriented at a 
predetermined angle relative to the longitudinal axes of the rail bars. 
Accordingly, when a train moves along the railroad track, one wheel of the 
train is transferred gradually from a previous rail bar to a succeeding 
adjacent rail bar so as to reduce the impact of the wheel with the end 
portion of the adjacent rail bar, thereby consequently generating less 
noise and vibration. 
However, the impact of the wheel with the end portion of the adjacent rail 
bar easily causes damage to a pointed end of the inclined end surface of 
the end portion of the adjacent rail bar. Thus, the rail bars of the 
railroad track have to be replaced frequently. 
SUMMARY OF THE INVENTION 
Therefore, the main objective of the present invention is to provide a rail 
joint which interconnects two successive rail bars of a railroad track for 
ensuring alignment of the successive rail bars and for keeping expansible 
spaces between any two of the successive rail tracks at equal distances so 
as to reduce vibration and noise generated by a train when the train 
passes over the rail joint. 
Another objective of the present invention is to provide a rail joint which 
has two complementary face units provided respectively on two adjacent end 
portions of the successive rail bars for avoiding damage to the adjacent 
end portions of the successive rail bars due to impact of one wheel of a 
train with the adjacent end portions of the successive rail bars. 
According to this invention, a rail joint for interconnecting two 
successive rail bars of a railroad track includes longitudinally aligned 
first and second guide rails. Each of the guide rails has a mounting end 
adapted to be secured to a respective one of adjacent end portions of the 
rail bars, a distal end opposite to the mounting end and spaced from the 
distal end of the other one of the first and second guide rails at an 
expansible space, and a downwardly and longitudinally extending dovetail 
projection. 
A connector is adapted to be fixed on the railroad track and is formed with 
an upwardly opening and longitudinally extending dovetail groove for 
receiving fittingly the dovetail projections of the first and second guide 
rails therein so as to maintain alignment of the first and second guide 
rails. 
The dovetail projection is an inverted T-shaped plate which has an upright 
web portion and two horizontal base portions. Each of the base portions 
extends transversely and outwardly from a respective one of two sides of a 
lower end of the web portion. 
The dovetail groove is an inverted T-shaped groove. The connector has a 
base plate which is adapted to be fixed on the railroad track and which 
carries the base portions of the inverted T-shaped plate thereon, and two 
longitudinally extending bent clamp plates which project upwardly from the 
base plate and which are spaced from each other to confine the inverted 
T-shaped groove therebetween. The clamp plates have vertical lower 
portions to flank the base portions of the inverted T-shaped plate, 
horizontal middle portions which extend respectively from upper ends of 
the lower portions and toward each other to cover the base portions, and 
vertical upper portions which extend respectively and upwardly from distal 
ends of the middle portions to flank the web portion of the inverted 
T-shaped plate. 
The connector further has means for fastening one of the first and second 
guide rails to the connector. The fastening means includes an aligned pair 
of holes formed respectively through the upper portions of the clamp 
plates, and a pin extending fittingly through the holes and through the 
web portion of the inverted T-shaped plate of said one of the first and 
second guide rails, thereby fastening said one of the first and second 
guide rails to the connector. 
The first guide rail has a first face unit formed on an end surface of the 
distal end thereof. The first face unit has two spaced flat edge sections 
with a predetermined longitudinal length of the first guide rail formed 
therebetween, and an inclined intermediate section interconnecting the 
flat edge sections. The second guide rail has a second face unit which is 
formed on an end surface of the distal end thereof and which complements 
the first face unit.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring to FIGS. 2 and 4, a preferred embodiment of a rail joint 30 
according to this invention is used for interconnecting two successive 
rail bars 50, 50' (see FIG. 4) of a railroad track. The rail joint 30 
includes longitudinally aligned first and second guide rails 31, 32 which 
are installed on two adjacent end portions of the rail bars 50, 50', and a 
connector 40 which is to be fixed on the railroad track to interconnect 
the first and second guide rails 31, 32 so as to ensure alignment of the 
first and second guide rails 31, 32. 
Each of the first and second guide rails 31, 32 has a mounting end secured 
to a respective one of the adjacent end portions of the rail bars 50, 50', 
such as by welding, and a distal end opposite to the mounting end and 
spaced from the distal end of the other one of the first and second guide 
rails 31, 32 at an expansible space 33. During assembly, the first and 
second guide rails 31, 32 are welded directly on two opposite end portions 
of the rail bar 50, as shown in FIG. 3. Then, several rail bars 50 are 
arranged to constitute a railroad track. 
Referring again to FIGS. 2 and 4, the first and second guide rails 31, 32 
further have head portions 311, 321 with top surfaces that are flush with 
the top surfaces of the rail bars 50, 50' (see FIG. 3) for carrying wheels 
of a train thereon, downwardly and longitudinally extending dovetail 
projections projecting from bottom sides of the head portions 311, 321 
respectively, and first and second face units formed respectively on end 
surfaces of the distal ends of the first and second guide rails 31, 32. In 
this embodiment, the dovetail projections are inverted T-shaped plates 
It is noted that the first and second guide rails 31, 32 are substantially 
similar in construction to each other. Therefore, only the first guide 
rail 31 will be described in detail in the following paragraph. 
The inverted T-shaped plate of the first guide rail 31 has an upright web 
portion 314 and two horizontal base portions 315, each of which extends 
transversely and outwardly from a respective one of two sides of a lower 
end of the web portion 314. The first guide rail 31 further has two 
longitudinally and downwardly extending flanges 312 which project 
downwardly from the bottom side of the head portion 311 and which are 
located at two sides of the web portion 314 of the inverted T-shaped plate 
thereof for defining two longitudinal retaining grooves 313 between the 
web portion 314 and the flanges 312. 
The inverted T-shaped plate of the second guide rail 32 also has an upright 
web portion 324 and two horizontal base portions 325 (only one is shown), 
while the web portion 324 further has a hole 3241 formed therethrough. Two 
longitudinal retaining grooves 323 (only one is shown) of the second guide 
rail 32, which are defined between the web portion 324 and two flanges 322 
(only one is shown), are aligned respectively with the retaining grooves 
313. 
The connector 40 includes a base plate 41 which is fixed on a sleeper 60 of 
the railroad track, as shown in FIG. 7, in a known manner, such as by 
means of bolts 61. Referring to FIGS. 2 and 5, the base plate 41 can carry 
the base portions 315, 325 thereon. The connector 40 further includes two 
longitudinally extending bent clamp plates 43 which project upwardly from 
the base plate 41 and which are spaced from each other to confine an 
upwardly opening and longitudinally extending dovetail groove 
therebetween. In this embodiment, the dovetail groove is an inverted 
T-shaped groove 42 for receiving fittingly the inverted T-shaped plates of 
the first and second guide rails 31, 32 therein. The champ plates 43 have 
vertical lower portions 431 to flank the base portions 315, 325 of the 
inverted T-shaped plates of the first and second guide rails 31, 32, 
horizontal middle portions 432 extending from upper ends of the lower 
portions 431 and toward each other to cover the base portions 315, 325, 
vertical upper portions 433 extending upwardly from distal ends of the 
middle portions 432 to flank the web portions 314, 324 of the inverted 
T-shaped plates of the first and second guide rails 31, 32, and 
longitudinal tongues 434 projecting upwardly from top surfaces of the 
upper portions 433 to engage the retaining grooves 313, 323 of the first 
and second guide rails 31, 32. In this way, the clamp plates 43 can 
maintain efficiently alignment of the first and second guide rails 31, 32 
to avoid violent vibration of the first and second guide rails 31, 32 when 
the wheels of the train pass over the rail joint 30, thereby reducing 
vibration and noise generated by the train so as to minimize unsteady 
movement of the train. 
In addition, the connector 40 further has means for fastening the second 
guide rail 32 to the connector 40. The fastening means includes an aligned 
pair of holes 4331 formed respectively through the upper portions 433 of 
the clamp plates 43 and aligned with the hole 3241 of the second guide 
rail 32. A pin 70 (see FIG. 4) extends fittingly through and is fixed 
within the holes 4331, 3241 by welding so as to fasten the second guide 
rail 32 to the connector 40. As a result, only the first guide rail 31 can 
expand with heat within the inverted T-shaped groove 42 of the connector 
40 and along a longitudinal direction toward the second guide rail 32. 
Thus, the expansible spaces 33 between adjacent pairs of the first and 
second guide rails 31, 32 can always be maintained at equal distances 
during thermal expansion. Therefore, the train can move smoothly and 
steadily along the railroad track as the wheels of the train pass over the 
rail joint 30 of this invention. 
Referring to FIGS. 2 and 6, the first face unit of the first guide rail 31 
has two spaced flat edge sections 317, 317' with a predetermined 
longitudinal length of the first guide rail 31 formed therebetween, and an 
inclined intermediate section 316 interconnecting the flat edge sections 
317, 317'. The second face unit of the second guide rail 32 complements 
the first face unit of the first guide rail 31 and also has two spaced 
flat edge sections 327, 327' and an inclined intermediate section 326. 
Referring to FIG. 6, when a train moves along the railroad track in a 
direction indicated by the arrow sign, one wheel 80 of the train travels 
from the flat edge section 317' of the first face unit of the first guide 
rail 31 toward the second guide rail 32. Then, the weight carried by the 
wheel 80 is transferred gradually from the inclined intermediate section 
316 of the first face unit of the first guide rail 31 to the inclined 
intermediate section 326 of the second face unit of the second guide rail 
32 Upon reaching successively first contact points (N11, N21), second 
contact points (N12, N22), and third contact points (N13, N23). Finally, 
the front edge of the wheel 80 is transferred entirely from the first 
guide rail 31 to the flat edge section 327 of the second face unit of the 
second guide rail 32 upon reaching fourth contact points (N14, N24). The 
gradual transfer of the weight carried by the wheel 80 from the first 
guide rail 31 to the second guide rail 32 can reduce impact of the wheel 
80 with the distal end of the second guide rail 32, thereby further 
reducing noise and vibration generated by the train. 
It is important to note that the flat edge sections 327, 327' of the second 
face unit of the second guide rail 32 have a larger strength for enduring 
impact of the wheel 80 so as to avoid damage such as that to the pointed 
end of the inclined end surface of the end portion of the conventional 
rail bar as described hereinbefore. 
While the present invention has been described in connection with what is 
considered the most practical and preferred embodiment, it is understood 
that this invention is not limited to the disclosed embodiment but is 
intended to cover various arrangements included within the spirit and 
scope of the broadest interpretations and equivalent arrangement.