US2906477A - Tongue rail locking mechanism - Google Patents

Description

Sept. 29, 1959 TAKUJI UEDA TONGUE RAIL LOCKING MECHANISM 3 Sheets-Sheet 1 Filed Oct. 19, 1955 Fig. 3

Sept. 29, 1959 Filed Oct. 19, 1955 TAKUJI UEDA 2,906,477 TONGUE RAIL LOCKING MECHANISM 3 Sheets-Sheet 2 nil Sept. 29, 1959 TAKUJI UEDA 2,906,477

TONGUE RAIL LOCKING MECHANISM Filed Oct 19, 1955 s Sheets-Sheet s F g- 3 Y United States Patent 7 2,906,477 I TONGUE RAIL LOCKING MECHANISM Takuji Ueda, Setagaya-ku, Tokyo, Japan Application October 19, 1955, Serial No. 541,476

Claims priority, application Japan October 22, 1954 9 Claims. (Cl. 246-318) This invention relates to improvements of locking mechanisms to maintain the contact of a tongue rail with a stock rail firmly by means other than a spring.

In a conventional spring switch mechanism, the tongue rail is pressed against the stock rail by means of a spring and, when a train passes over the switch, the assembly is spread out by the flanges of the car wheels of the train in order that the train may pass safely. However, traflic accidents may happen where the tongue rail is in contact with the stock rail only by means of a spring, because repeated opening motions of the tongue rail may occur due to shock caused by the passing of a high speed train.

An object of this invention is to provide an improved locking mechanism for a point switch; that is, for fixing a tongue rail to a stock rail by utilizing a dead-point alignment of a link mechanism in order to assure the locking thereof.

A feature of this invention is to provide a spring switch lever with a tongue rail locking mechanism.

Another feature is to provide a spring switch mechanism with a tie bar incorporated with the said locking mechanism.

Still another feature of this invention is to provide a complete locking mechanism which, by eliminating excessive stress on the link assembly in the said tongue rail locking mechanism, prevents a failure thereof when a train passes over it.

The accompanying drawings illustrate the embodiments of this invention.

In the drawing:

Figure l is a plan view of a part of a rail arrangement showing one example of its application;

Figure 2 is a similar plan view showing another feature;

Figure 3 is a skeleton diagram of the principal mechanism;

Figure 4 is a diagrammatic illustration with a train spreading the tongue rail;

Figure 5 shows a plan view of still another embodiment of this invention, including a special tie bar;

Figure 6 is a plan view of an embodiment with another special tie bar;

Figure 7 is a sectional view of the tie bar in Figure 6, and taken through line 7-7;

Figure 8 is an enlarged partial sectional view of a connecting link shown in Figure 6;

Figure 9 is a similar plan view showing another 'em bodiment of this invention; and

Figure 10 is an enlarged partially sectional view of the connecting link referred to in Figure 9. i

In Figure 1, elements 11 and 12 are the stock rails of a track and 13 and 14 the tongue rails. A rectangular bell crank is pivoted on the axle 17 at the center line of the track on a bed plate 16 which is fixed on the sleeper, the end of each arm 18A, 18B of the bell crank being connected to the inward transverse projections 19A, 19B of the tongue rail 13, 14 by links 20A and 20B re spectively. The locking mechanism is of the same strucseen in Figure 4, an allowance equal to the maximum,

ture on both side tongue rails except as particularly defined. When one of the tongue rails for example, rail 13 (the right one) contacts the stock rail 11, as shown in the drawing, the right arm 18A of the bell crank and the projection 19A of the tongue rail 13 are so arranged that they make a straight line together with the right link 20A perpendicular to the tongue rail 13. Hence, the tendency for the said tongue rail to part from the stock rail is completely prevented by the dead-point alignment of the said three elements. The provision of a spring 21, in tension, one end of which is connected at the center line of the track to the plate 16 and the other on the bell crank middle arm 18C, will make the above feature even more efiective, strengthening the counterclockwise movement of the bell crank.

The middle or the third arm 18C is rigidly connected to the bearing or hub portion of the bell crank as an integral part of it, one end of which is connected to the switch lever by means of a connecting rod 22. By a turn: ing of the switch lever in the opposite direction, the connecting rod 22 is pulled leftwards in Figure 1, easily reversing the direction of the arms 18A, 18B by the turning of the bell crank. The left tongue rail 14 then contacts the left stock rail 12, arranging the above three elements in a dead-point alignment, and further spacing and keeping the right tongue rail 13 apart from the stock rail 11. As in the first case, this alignment absolutely prevents the unlocking of the left tongue rail 14, and a train can pass safely.

Another embodiment of this invention is illustrated in Figure 2. Here, the said bell crank is pivoted about the axle 23 on the opposite side of the sleeper and the tongue rails 13 and 14 are connected by the tie bar 24, which is connected to the connecting rod 25 of the switch. The switching is actuated by the transverse motion of the said tie bar as in the ordinary type. In this case, the spring 21 acts in compression to turn the bell crank.

In both cases mentioned above, however, the bell crank need not necessarily be rectangular, and the said deadpoint alignment is as well applicable to cases where a separate crank lever is employed for each of the tongue rails respectively.

In the second example, when the tongue rails 13 and 14 are switched to the left by the tie bar 24, the turning of the rectangular bell crank will eflect a much bigger movement of the left tongue rail and less on the right where the rotational angle 0 of the bell crank is smaller than the 45 as shown in Figure 3. Hence, if the tie bar is fixed rigidly to the tongue rails 13 and 14, it can easily be realized that tensile or shearing stress occurs in the structural members and this may cause trouble.

In the spreading out of the tongue rail by a train as difference between the displacements a and b of the tongue-rail is made between the tongue rails 13 and 14 and the tie bar 24. vThe connecting plates 26 and 27 are fixed on the insides of the tongue rails 13 and 14 and pins 30 and 31 are inserted slidably in slots 28 and 29 of the connecting plates. Pins 30 and 31 on the tie bar 24 are located at the outer ends of the slots 28 and 29, respectively, as shown in Figure 2.

In Figure 2, in the first stage of the leftward movement of the tie bar'24 by the switch lever, though the leftward movement of the right tongue rail 13'caused by counter-clockwise rotation of the bell crank is comparatively smaller than that of the left tongue rail, no'compulsory force will act on the right tongue rail at the slow leftward movement of it, because the right side pin 30 of the tie bar 40 can move freely along the slot 28. As the angle 0 is increased to more than 45 the efiect of the bell crank on the movement of the tongue rails will be completely reversed, but due to the free rightward movement of the pin 31 in the left side slot 29, there will occur no undesirable stress. The right tongue rail will be moved to the left safely, and thus the switching of the tongue rail will be very smooth.

Figure 5 shows another embodiment of this invention. Here, the tongue rail 13 is normally in contact with the right stock rail 11 by the force of the compression spring 32 as in an ordinary spring switch. At the same time, as seen in the former examples, the right arm 18A of the bell crank and the link 20A and the inward projection 19A of the right tongue rail are so arranged on a deadpoint alignment, as to prevent the right tongue rail 13 from getting out of order and to keep it normal notwithstanding the effect of any undesirable vibration of the spring caused by the shock of a passing train. Hence, in order to compensate for the difference between the displacement of the right and left tongue rails 13 and 14 caused by the turning of the bell crank, the tie bar is interlocked with the switch in the following way. The tie bar 24 is rigidly fixed only to the right tongue rail 13 by the pin 33, and connected particularly to the left tongue rail by the second pin 35 which is freely slidable in the slot 34 of the connecting plate 27, said pin 35 being at the left end of the slot 34 at a normal position as shown in Figure 5. When the trailing train arrives, as shown in Figure 4, the left tongue rail 14 is spread out by the flanges of the wheels of the train and the bell crank is turned counter-clockwise by means of the link 20B. In the first stage of this rotation, the leftward displacement of the left arm 18B of the bell crank is comparatively larger than that of the right arm 18A, so the movement of the left tongue rail 14 is not the same as that of the right tongue rail 13; however, as the left tongue rail 14 is connected slidably with the pin 35 set on the tie bar by the slot 34 of the connecting plate 27, the larger displacement of the left tongue rail is absorbed by the rightward movement of the second pin 35 in the slot 34. In the latter stage of the counter-clockwise turn of the bell crank, though the displacement of the tongue rails will be reversed, the smaller displacement of the left arm 1813 in this case is compensated for by the leftward sliding of the second pin 35 in the slot 34; thus without giving any undesirable stress on the structural members, the left tongue rail 14 will be held in its required position taking a dead-point alignment where the straight line through the left link 20B and the arm 18B of the bell crank may pass the pivot 23 of the bell crank, as will be easily understood from the above explanation, and is locked firmly. After the train has passed, the bar 24 is displaced to the right by the force of the compres sion spring 32 of the switch, and turns the bell crank clockwise. In the first stage of this movement, the displacement of the right link 18B is larger than that of the left link 18B, but the second pin 35 on the tie bar 24 slides to the left freely in the slot 34 of the connecting plate 27 and exerts no undesirable tension on the left tongue rail 14. In the latter stage too, though the situation is reversed, it will be readily understood that no trouble will occur.

In the above-mentioned embodiments, the connection of the tie bar with the tongue rail is made by means of pins; but it is not always desirable, because of structural strength, to transmit the moving power to the tongue rail by means of pin or bolt joints. In Figure 6 and Figure 7, straps 36 and 37 are attached on the tie bar 24 and butt-jointed to the inward ends of the connecting plates 26 and 27, which are provided on the insides of the tongue rails 13 and 14 as in the former instances. Accordingly, the movement of the connecting rod 25 and the tie bar 24 to the left, by the operation of the switch lever, will cause the left strap 37 to push leftward the left tongue rail and make the bell crank turn counterclockwise. In the first stage of this rotation, the movement of the right tongue rail 13 to the left is not so much as that of the left tongue rail 14, but as the right strap 36 of the tie bar 24 abuts only on the inside of the connecting plate 26 of the right tongue rail 13, the leftward movement of the tie bar 24 does not positively pull the right tongue rail 13, and so, even if the slow movement of the right tongue rail 13 is so retarded that it does not follow the movement of the tie bar 24, there will be only a simple slip and no stress between the tie bar and the right tongue rail. In the latter half of the counter-clockwise rotation of the bell crank, the right tongue rail 13 moves faster than the left tongue rail 14, so as to compensate for the gap between the right strap 36 and the connecting plate 26 of the right tongue rail 13 caused by the slip in the first half, and no trouble will occur. The bolts 38 in the joint of the above illustration, Figure 7, serve only to guide the slip.

In the reverse operation of the switch, everything will operate in reverse order to the above. In short, as the movement between the tie bar and the tongue rail is transmittted by means of a butt-joint and not by bolts, the reliability of the mechanism is assured by avoiding failure of the bolts caused by an excessive shearing stress.

It is to be noticed that the tongue rail 13 is pressed strongly against the stock rail 11 by the flanges of the wheels when a train passes. In general, the total length of the arm 18A of the connecting rod 20A and of the Figure 6 and Figure 8, an expansion joint is fitted on the said three parts, an example of which is shown in Figure 8; that is, the connecting link is composed of a connecting rod 20A, a threaded bolt 40 which is freely inserted into the connecting rod 20A, a compression spring 39 mounted between the connecting rod 20A and a cap 41 fixed at the end of the threaded bolt 40, and a nut 42 is screwed on the bolt 40 abutting the end of the rod 20A, so that it prevents the bolt 40 from entering fully into the connecting rod 20A. A washer 43 and second nut 44 lock the first nut 42 on the bolt 40; as the length of the bolt 40 inserted in the connecting rod 20A can be adjusted by means of the first nut 42 after a loosening of the second nut 44, the length of the total link members may be adjusted easily when laying down the railway track, so as to allow the tongue rail 13 to be forced against the stock rail 11 when desired.

Another embodiment of this invention, particularly provided with a device for absorbing the effect of the excessive pressure of the tongue rail on the stock rail, is shown in Figures 9 and 10. In this embodiment, the connecting member is composed of two pieces, one threaded bolt 20A1 and a yoke 20A2. A pin 44 set on the yoke 20A2 is inserted slidably into a slot 45 provided at the end of the transverse projection 19A. When the elements 18A, 20A1, 20A2 and 19A are secured as in above embodiments, the projection 19A on the tongue rail 13 cannot move leftwards, as the pin 44 abuts on the right end of the slot 45; that is to say, the tongue rail 13 is locked against vibration, but when it is pressed on the stock rail 11 by a passing train, the projection 19A can be deviated a little to the right owing to the pin 44 sliding in the slot 45.

This construction has the advantages of avoiding excessive tensile stress on the dead-point alignment of the assembly as the tongue rail is forced against the stock rail by the passing train.

What is claimed is:

1. In a rail arrangement including spaced and parallel stock rails defining a center line therebetween, and tongue rails between the stock rails and spaced such that only one tongue rail can contact a stock rail at one time; apparatus comprising a stationary plate between the stock rails, a bell crank member pivoted on the plate at the center line and including two angularly spaced arms, first and second means respectively connected to the tongue rails, a link coupling one arm to said first means, and another link coupling the other arm to said second means, a control member connected with the bell crank member for controllably pivoting the same between two extreme positions, and a spring coupled to said plate at the center line and to said bell crank member at a point which crosses the center line with the bell crank member being pivoted from one extreme position to the other whereby pivotal motion of the bell crank member is resisted, the lengths of said links being such that, with a tongue rail engaging a stock rail, the associated arm, link and means and pivot point of the bell crank lever are linearly aligned to supplement the action of said spring.

2. Apparatus as claimed in claim 1 comprising n'urther spring means for loading each of said tongue rails to maintain the rail normally in contact with the stock rail biassed toward said stock rail.

3. Apparatus as claimed in claim 1 comprising a tie bar, means on the tongue rails adapted for engaging the tie bar, and connections between the latter said means and the tie bar, at least one of said connections being a lost motion connection.

4. Apparatus as claimed in claim 3 wherein all connections are lost motion connections.

5. Apparatus as claimed in claim 3 wherein the latter said means and said tie bar collectively comprise pins and define elongated slots accommodating said pins.

6. Apparatus as claimed in claim 3 wherein the latter vsaid means are plates detachably engaging the tongue rails, said connections comprising straps on the tie bars for loosely engaging the latter said plates and bolts on the tie bars for guiding the latter said plates into engagement with the straps.

7. Apparatus as claimed in claim 3 wherein said links comprise means for adjusting their respective lengths.

8. Apparatus as claimed in claim 3 wherein said links are resilient members for facilitating the linear alignment.

9. Apparatus as claimed in claim 8 wherein said links include adjustment means for adjusting their respective resiliencies.

References Cited in the file of this patent UNITED STATES PATENTS 965,243 Snow July 26, 1910 1,509,777 Qualls Sept. 23, 1924 2,375,890 Black May 15, 1945 FOREIGN PATENTS 7,666 Australia May 3, 1933 81,237 Austria Sept. 10, 1920 662,298 France Mar. 18, 1929 7,716 Germany Dec. 16, 1879 14,520 Netherlands May 15, 1926

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