THREE-WAY RAILWAY SWITCHING POINTS

Abstract: Railway switching points (10) to selectively switch a first track road (11) between second, third and fourth track roads (12, 13, 14) has two pairs of movable tongues (27, 28) both movable between respective first and second positions. When both pairs of movable tongues (27, 28) are in their first positions, the first track road (11) is switched to the second track road (12), when both pairs (27, 28) are in their secured positions, the first track road (11) is switched to the fourth track road (14), while the first track road (11) is switched to the third track road (13) when one pair (27, 28) is in its first position and the second pair (28) is in its second position. An actuator (37) has a slotted plate or cog (38) engaged by actuator arms (35, 36) to move the pair of tongues (27, 28) between the first and second positions.

Description: Tit le : " THREE-WAY RAILWAY SWITCHING POINTS ' ■ BACKGROUND OF THE INVENTION ( 1 ) Field of the Invention This invention relates to switching points for railway tracks: Throughout the specification, the term "railway tracks" will also include, inter alia, tramway- and conveyor tracks. (2 ) Prior Art Conventional railway switching points only enable a main track road to be divided into two roads e.g. two divergent roads or the main road and a spur road. Therefore, where two spur roads are required, to diverge from the main road, two sets of switching points must be used and these must be spaced along the main road. In a marshalling yard, where there are a number of main- and spur roads, considerable valuable space is taken up in providing for all the sets of switching points necessary to enable-a train to be. outed between different roads in yard. SUMMARY OF THE PRESENT INVENTION It is an object of the present invention to provide switching points for railway tracks which enables a main track road to be divided into three roads, e.g. a combination of the main road and two spur roads. It is a preferred object to provide switching points which are relatively compact. It is a further preferred object to provide switching points which are simple and inexpensive to manufacture and which are reliable in operation. Other preferred objects of the present invent¬ ion will become apparent from the following description. In a broad aspect, the present invention resides in switching points for railway tracks to select¬ ively switch a first track road to second, third, or fourth track roads, the switching points including: a first pair of movable tongues arranged to move in unison; a second pair of movable tongues arranged to move in unison; and means operable to move the pair of tongues between respective first and second positions, so arranged that: when the first and second pair of tongues are both in their respective first positions, the first track road is switched to the second track road; when the first pair of movable tongues is in its first position and the second pair of movable tongues is in its second position, the first track road is switched to the third track road; and when the first and second pairs of movable tongues are both in their respective second positions, the first track road is switched to the fourth track road. Preferably the third road is a continuation of the first road, and the second and fourth roads diverge to opposite sides of the first road e.g. as spur roads. Preferably the inner curved track rails of the second and fourth road are provided as divergent con- tinuations of the respective rails of the first road. Preferably the ends of the third road rails are spaced from, but aligned with, the first road rails and the ends of the outer curved track rails of the second and fourth roads are spaced inwardly from the ends of the third track rails. Preferably the movable tongues of the first pair of tongues are hingedly mounted adjacent the end of the third track rail on the side of the fourth road and the outer track rail of the fourth road respectively, while the movable tongues of the second pair of tongues are hingedly mounted adjacent the ends of the third track rail on the side of the second road and the outer track rail of the second road respectively. Preferably the free ends of the movable tongues engage, or lie against, the track rails of the first road at or adjacent to, the divergent of the first road track rails. Suitable mechanical, electrical, hydraulic and/or pneumatic actuators, circuits and controls may be used to selectively move the pairs of movable tong¬ ues between their respective first and second positions. The choice of this equipment may be tailored by the user to suit the controls and signals of the railway system. BRIEF DESCRIPTION OF THE DRAWINGS To enable the invention to be fully understood, a number of preferred embodiments will now be described with reference to the accompanying drawings, in which: FIG. 1 is a plan view of the switching points and a mechanical actuator therefore with the first road switched to the third road; FIG. 2 is a sectional side view of the actuator taken on line 2-2 on FIG. 1; FIGS. 3 and 4 correspond to FIGS. 1 and 2 with the first road switched to the second road; FIGS. 5 and 6 correspond to FIGS. 1 and 2 with the first road switched to the fourth road; FIG. 7 is a perspective view of the pairs of movable tongues; FIG. 8 is a front view of a manual actuator in its position switching the first road to the third road; FIG. 9 is a side view of the actuator of FIG. 8; FIGS. 10 and 11 are views correspondind to FIGS. 8 and 9 with the first road switched to the fourth road. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The switching points 10 of the present invention enable the first (or main) track road 11 to be selectively switched between the second, third and fourth track roads.12, 13, 14 respectively. As shown, the third road 13 is a direct continuation of the first road 11. The first road 11 has spaced rails 15 and 16 *, _ which are respectively connected to the inner curved 0 rails 17, 18 of the second and fourth roads 12, 14 via divergent joining rails 19 and 20. The rails 21, 22 of the third track road 13 are aligned with, but spaced from the rails 15, 16 respect¬ ively, while the outer curved rails 23, 24 of the second 5 and fourth track roads 12, 14 are spaced inwardly, and commence adjacent the rails 21, 22, the gauge between the rails 17, 23 and 18, 24 for the track roads 12, 14 being maintained along their length. Where the rails of the different track roads cross, clearance slots 25 to allow the passage of the wheel flanges on the rolling stock are provided in the conventional manner, together with the conventional heel plates 26 to maintain the wheels on the rails. Referring to FIG. 1, the switching points 10 includes two pairs of movable tongues 27, 28 between the divergent joining rails 19,20. The first pair 27 of tongues 29, 30 are pivot¬ ally connected to the rails 22, 24 of the third and fourth track roads 13, 14 respectively, while the second pair 28 of tongues 31, 32 are pivotally connected to the rails 23, 21 of the second and third track roads 12, 13 respectively. The tongues in each pair 27, 28 (connected by adjustable stabilizing links 33, 34) move in unison but the pairs are independently operable by suitable actuator arms 35, 36 connected to an actuator 37 to switch the first track road 11 to the second, third or fourth track roads. The operation of the switching points 10 will now be described. (A) First track road 11 to second track road 12 (see FIG. 3). The pairs of tongues 27, 28 are operated to bring both tongues 29 and 31 into engagement with the rail 16 of the first track road, while tongues 30 and 32 are simultaneously moved away from the rail 15, •, . thereby connecting the rails 15 and 16 of the first track road 11 to the rails 17, 23 respectively of the second'track road 12. (B) First track road 11 to third track road 13 (see FIG. 1 ). The actuator 37 moves the actuator arm 36 and is operated to move the pair of tongues 28, so that the tongue 31 is moved away from rail 16 and tongue 32 is moved into engagement with rail 15, thereby connect¬ ing the rails 15, 16 to rails 21, 22 of the third track road. (C) First track road 11 to fourth track road 14 (see FIG. 5). The actuator is now operated to move actuator arm 35, and thereby the pair of tongues 27 so that tongue 29 moves away from rail 16 and tongue 30 moves into engagement with rail 15. The rails 15, 16 are now conn¬ ected to the rails 24, 18 respectively of the fourth track road 14. As shown above, by simply moving the two pairs of tongues 27, 28, the first track road 11 is easily and quickly switched to any one of the other track roads 12 to 14. While the embodiment described shows a spur track road 12, 14 diverging to either side of the main track road 11, the present invention may also be used to switch a main track road 11 to either of two spur track roads on one side of it (e.g. track roads 12 and 13 become -6- the spur track roads and track road 14 the continuat¬ ion of the main track road 11). The one set of switching points 10 replaces the two sets of convent¬ ional switching points which would be normally required. Referring now to FIG. 7 which illustrates the construction of the movable tongues 29-32, the outer tongues 29, 32 of the pairs 27, 28 respectively of conventional configuration for switch point tongues. The inner tongues 31, 30 of the pairs 27, 28 are designed to nestle in against the inner faces of the outer tongues 29, 32 respectively. The inner faces of the outer tongues may have an inclined upper portion or may be stepped to receive horizontal flanges on the inner tongues to provide supporting engagement between the movable tangles when railway rolling stock pass over the switching points. The actuator arms 35, 36 and the stabilizer arms 33, 34 interconnecting the pair of tongues 27, 28 will be slidably journalled for smooth movement of the pairs of tongues as they are moved. A mechanical actuator 37 suitable for oper¬ ating the switching points 10 is shown in FIGS. 1 and 2. The actuator 37 has a main cog 38 rotatably journalled on a base 39 and driven by a motor M (which may be electric, hydraulic or pneumatic) and connected to the cog 38 by a suitable drive means 40. The cog 38 has a machined track 41 in its upper face. The track 41 has a circular centre arc 42, which extends from approximately 220° of rotation, connected to a circular inner arc 43 which extends for approximately 40 of rotation, by a pair of inwardly directed sections 44, 45 each of which extend for approximately 50° of rotation. The actuator arras 35, 36 extend over the cog 38 and are slidably journalled in support posts 46. A bearing 47 is provided on the underside of each actuator arm and the bearings 47 are engaged in the track 41 in the manner of cam followers. To provide additional stability for the actuator arms 35, 36, an elongated nose 48 on the actuator arm 36 is slidably journalled in a bore (not shown) in actuator arm 35. A second cog 48, rotatable about a vertical axis, is engaged with the cog 38 but has a diameter one-fourth the diameter of the latter. A pair of locking bars 49 are selectively engageable in slots 50 in the actuator arms 35, 36 to lock the pairs of tongues 27, 28 in the respective first and second positions. The locking bars 49 are supported in horizontal guides and are operated by a bellcrank 50 and link 51 connected to the cog 48. The operation of the actuator will now be described. To switch the first track road 11 from the third track road 13 (see FIG. 1) to the second track road 12 (see FIG. 3), the motor M rotates the cog 38 in a clockwise direction. During the first 20° of rotation, both bearings 47 remain in outer arc 42 and neither actuator arm 35, 36 is moved. However, cog 48 is rotated through 80° to cause locking bars 49 to be withdrawn from the slots 50 in the actuator arms. During the next 50° of rotation, the bearing on actuator arm 35 remains in the outer arc and so the first pair of tongues 27 remain in their first position (see FIGS. 1, 3). However, the bearing on the actuator arm moves through the inwardly directed section 45, pulling the actuator arm 36 so that the second pair of tongues 28 are moved from their second position (see FIG. 1) to their first position (see FIG. 3). During the final 20° of rotation of cog 38, cog 48 completes the final 80 of its travel to cause the lock- ing bars 49 to re-engage the slots 50 in the actuator arms. To switch first track road 11 f om third track road 13 to the fourth track road 14, the rotation of the cog 38 is reversed (i.e. cog 38 is rotated in an anti-clockwise direction). To switch the first track road 11 from the second track road 12 to the fourth track road 14 (or vice versa), the cog 38 is rotated through 180° in either direction, the first track road 11 being switched to third track road 13 as an intermediate step. Depending on the type of motor M used, the cog 38 : may always be rotated in one direction or may be reversed to effect the switching of the points. Referring now to FIGS. 8 to 11, a manual actuator 52 for the switching points 10 is shown. The actuator 52 has an A-shape frame 53 with a shaft 54 at its apex. A control lever 55 is pivotally mounted on the shaft 54 and has a curved slot 56 in its lower portion. A pair of primary levers 57, 58 are also pivoted on the shaft 54 and each has a pin 59 received in the slot 56. Secondary levers 60, 61 are pivotally mounted on posts 62 on the frame 53 and each has a pin 64 at its upper end engaged in a slot 65 in the lower ends of the primary levers 57, 58. Thrust springs 66 are connected by blocks 67 to the lower ends of the secondary levers 60, 61 to urge and retain them in either a vertical position or an inclined position (see FIG. 10). Pins 68 intermediate the length of the sec- ondary levers 60, 61 engage hinged links 69 at the ends of the actuator arms 35, 36 and which are journalled for horizontal sliding movement in supports 70. A control wedge 71 is mounted on a pin 72 on the control lever 53, the pin being engaged in a slot 73 which enables the control wedge to move vertically. A ' wedge gear 74 is mounted on a pin on the control lever and meshes with a control gear 75 fixed on the main shaft 54. A wedge arm 76 inter¬ connects pins 77, 78 on the wedge gear 7^ and control wedge 71. In its upright, or central position, of the control lever 53, first track road 11 is switched to third track road 13, with the actuating arm 35 plac¬ ing the first pair of movable tongues 27 in their first position and the actuating arm 36 placing the second pair of tongues 28 in their second position. To switch the first track road 11 to the fourth track road 14, the control lever 53 is swung to the left as shown in FIGS. 10 and 11. As the control lever 53 moves, the primary lever 57 moves inwardly and the wedge gear commences its rotation about the control gear 75 to lower the control wedge 71 via wedge arm 76. When the primary and secondary levers 57, 60 become aligned, the thrust spring 66 is fully compress- ed. As the control lever 58 continues to move, the levers 57, 60 go "over-centre", urged by the expanding thrust spring. At the end of the travel of the control lever 53, the control wedge is fully descended and the switching points 10 are locked with the first pair of movable tongues 27 moved to its second position. As the control lever 53 is moved, slot 56 acts as a lost-motion connection to primary lever 58 so that actuating arm 36 is not moved. To reset the first track road 11 to the third track road 13, the control lever is returned to its upright position, while moving it to the right will switch the first track road 11 to the second track road 12. The embodiments described and illustrated are by way of illustrative examples only, and various changes and modifications may be made thereto without departing -10- from the scope of the present invention defined in the appended claims.

Claims: CLAIMS: 1. Switching points for railing tracks to selectively switch a first track road to second, third or fourth track roads, the switching points including: a first pair of movable tongues arranged to move in unison; a second pair of movable tongues arranged to move in unison; and " means operable to move the pairs of tongues between respective first and second positions, so arranged that: when the first and second pairs of tongues are both in their respective first positions, the first track road is switched to the second track road; when the first pair of movable tongues is in its first position and the second pair of movable tongues is in its second position, the first track road is switched to the third track road; and when the first and second pairs of movable tongues are both in their respective second' positions, the first track road is switched to the fourth track road. 2. Switching points according to claim 1 wherein: the inner curved track rails of the second and fourth road are provided as divergent continuations of the respective rails of the first road. 3. Switching points according to claim 2 wherein: the ends of the third road rails are spaced from, but aligned with, the first road rails and the ends of the outer curved track rails of the second and fourth roads are spaced inwardly from the ends of the third track rails. 4. Switching points according to claim 1 wherein: the movable tongues of the first pair of tongues are hingedly mounted adjacent the end of the third track rail on the side of the fourth road and the outer track rail of the fourth road, respectively, while the movable tongues of the second pair of tongues are hingedly mounted adjacent the ends of the third track rail on the side of the second road and the outer track rail of the second road respectively. 5. Switching points according to claim 4 wherein: the free ends of the movable tongues "engage, or lie against, the track rails of the first road at, or adjacent to, the divergent of the first road track rails. ' 6. Switching points according to claim 1 wherein: the means to move each pair of tongues includes an actuator arm connecting the pair of tongues to an actuator, the tongues of each pair being inter¬ connected by actuating links. 7. Switching points according to claim 6 wherein: the actuator has a rotary cog or plate with a track in its upper face, the track having respective arc portions of differing circumference; and each actuating arm is operably engaged with the track, so arranged that as the cog or plate is rotated, only one of the pairs of tongues is moved between its first and second positions at any time to change the switching of the first track road. 8. Switching points according to claim 6 wherein: the actuator has a control lever connected to the actuating arms by a respective pair of pivotal levers, lost motion means interconnecting the control lever and the pivotal levers so that only one pair of pivotal levers will be moved as the control lever is moved to change the switching of the first track road. 9 t Switching points according to claim 7 or claim 8 wherein: locking means releasably lock the actuator in each position when the first track road is switched to one of the second, third or fourth roads. 10. Switching points for railway tracks substant¬ ially as hereinbefore described with reference to FIGS. 1, 3 and 5 of the accompanying drawings.

Inventors: GLASPY JAMES KEITH, GLASPY, JAMES, KEITH
Applicants: GLASPY JAMES KEITH, GLASPY, JAMES, KEITH
Application year: 1986
Main classification: E01B7
IPC codes: E01B7