GB2122790A - Lever mechanism - Google Patents

Abstract

A manually-operable lever box for operating the points of a railway switch mechanism has its operating lever (19) mounted on a pivot (18) situated within the lever box (10). This enables the lever to lie flush with or below the level of the track, so that it cannot be struck by a passing train. <IMAGE>

Description

SPECIFICATION Lever mechanism This invention relates to lever mechanisms for operating the points of a railway switch mechanism. It is especially concerned with the provision of a lever box of the manually operable type.

Hand-controlled lever boxes are well known, and have been in operation for a very large number of years. Basically the mechanism comprises a spring toggle system in operative connection with the switch and tending to hold the switch in either of two positions, and a hand lever normally occupying a common rest position (whether the toggle mechanism is set in one position or the other) and adapted when operated to change the position of the toggle mechanism from one extreme to the other and consequently to reverse the switch or points through the connection thereto of the toggle mechanism. A basic known type of lever box is illustrated in Figure 1 of the accompanying drawings.

In all hand-operated lever boxes the operating lever is pivotally mounted on the top of the box.

Thus, in Figure 1, the lever 1 is mounted on a pin 2 held between brackets 3 welded to the top plate 4 of the box. Movement of the lever 1 about the pivot pin 2 causes a plunger 5 to operate a bell crank mechanism 6 to reverse the points.

The fact that the operating lever 1 is situated on top of the lever box means that in operation it is mounted above the level of the railway track.

This has disadvantages, in that the lever can be struck by a passing train, or attachment thereto, with possibly serious consequences. It is an object of the present invention to provide a lever box which does not suffer from this disadvantage.

According to the invention there is provided a lever box in which the manually-operable lever is mounted on a pivot situated within the box. This enables the lever to lie flush with or below the level of the track. It cannot, therefore, be struck by a passing train.

An embodiment of the invention will be described with reference to Figures 2 to 5 of the accompanying drawings, in which Figure 2 is a side elevation of a lever box; Figure 3 is a schematic plan view of the box of Figure 2; Figure 4 is an end elevation of the box of Figure 2 attached to a switch blade; and Figure 5 is an elevation, on a larger scale, of the operational end of the lever.

Referring to Figures 2 to 5 of the drawings, a lever box 10 comprises a body 11 and a top plate 1 2. The body 11 contains the usual spring toggle and bell crank mechanisms 13, 14 respectively.

Rotation of the bell crank mechanism 14, and hence reversal of the disposition of the toggle mechanism 13, with consequent switching of the points through a connecting rod 15, is achieved by a horizontally-movable plunger 16. This operation is identical to that of known lever boxes.

Mounted between two retaining brackets 1 7 situated within the body 11 is a pivot pin 18, and fulcrumed on pivot pin 18 is an operating lever 19. The lever 19 lies flush with the top plate 12 of the lever box 10. The operational end of the lever 19, i.e. that portion situated within the body 11, is illustrated in Figure 5. It consists of a hooked end portion 20 having two reaction faces 21 and 22 respectively. The hooked end portion 20 'of the lever 1 9 is retained within a cut-out 23 formed in an enlarged end portion 24 of plunger 1 6. Cut-out 23 has-a reaction surface 25 which is engaged, in the position of the mechanism shown in the drawings, by reaction face 21.

In order to operate the lever box of the invention the lever 19 is manually grasped and is pivoted about the pivot pin 1 8. The cam surface formed by reaction faces 21 and 22 of the lever 19 acts on face 25 of the plunger 1 6 to cause the plunger to move horizontally, left-to-right as viewed in Figures 2 and 3. Plunger 1 6 contacts and swivels the bell crank mechanism 14, with consequent movement of the spring toggle mechanism 13, the connecting rod 1 5 and a switch rail 26 to which connecting rod 1 5 is fixed.

After switching the points, the lever 1 9 is returned to its initial horizontal position, flush with the top plate 12 and, as can be seen from Figure 4, below the level of adjacent rail 27.

Claims

1. A lever box in which a manually operable lever is mounted in a pivot situated within the box.

2. A lever box as claimed in claim 1, substantially as described with reference to the drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (2)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Lever mechanism This invention relates to lever mechanisms for operating the points of a railway switch mechanism. It is especially concerned with the provision of a lever box of the manually operable type. Hand-controlled lever boxes are well known, and have been in operation for a very large number of years. Basically the mechanism comprises a spring toggle system in operative connection with the switch and tending to hold the switch in either of two positions, and a hand lever normally occupying a common rest position (whether the toggle mechanism is set in one position or the other) and adapted when operated to change the position of the toggle mechanism from one extreme to the other and consequently to reverse the switch or points through the connection thereto of the toggle mechanism. A basic known type of lever box is illustrated in Figure 1 of the accompanying drawings. In all hand-operated lever boxes the operating lever is pivotally mounted on the top of the box. Thus, in Figure 1, the lever 1 is mounted on a pin 2 held between brackets 3 welded to the top plate 4 of the box. Movement of the lever 1 about the pivot pin 2 causes a plunger 5 to operate a bell crank mechanism 6 to reverse the points. The fact that the operating lever 1 is situated on top of the lever box means that in operation it is mounted above the level of the railway track. This has disadvantages, in that the lever can be struck by a passing train, or attachment thereto, with possibly serious consequences. It is an object of the present invention to provide a lever box which does not suffer from this disadvantage. According to the invention there is provided a lever box in which the manually-operable lever is mounted on a pivot situated within the box. This enables the lever to lie flush with or below the level of the track. It cannot, therefore, be struck by a passing train. An embodiment of the invention will be described with reference to Figures 2 to 5 of the accompanying drawings, in which Figure 2 is a side elevation of a lever box; Figure 3 is a schematic plan view of the box of Figure 2; Figure 4 is an end elevation of the box of Figure 2 attached to a switch blade; and Figure 5 is an elevation, on a larger scale, of the operational end of the lever. Referring to Figures 2 to 5 of the drawings, a lever box 10 comprises a body 11 and a top plate 1 2. The body 11 contains the usual spring toggle and bell crank mechanisms 13, 14 respectively. Rotation of the bell crank mechanism 14, and hence reversal of the disposition of the toggle mechanism 13, with consequent switching of the points through a connecting rod 15, is achieved by a horizontally-movable plunger 16. This operation is identical to that of known lever boxes. Mounted between two retaining brackets 1 7 situated within the body 11 is a pivot pin 18, and fulcrumed on pivot pin 18 is an operating lever 19. The lever 19 lies flush with the top plate 12 of the lever box 10. The operational end of the lever 19, i.e. that portion situated within the body 11, is illustrated in Figure 5. It consists of a hooked end portion 20 having two reaction faces 21 and 22 respectively. The hooked end portion 20 'of the lever 1 9 is retained within a cut-out 23 formed in an enlarged end portion 24 of plunger 1 6. Cut-out 23 has-a reaction surface 25 which is engaged, in the position of the mechanism shown in the drawings, by reaction face 21. In order to operate the lever box of the invention the lever 19 is manually grasped and is pivoted about the pivot pin 1 8. The cam surface formed by reaction faces 21 and 22 of the lever 19 acts on face 25 of the plunger 1 6 to cause the plunger to move horizontally, left-to-right as viewed in Figures 2 and 3. Plunger 1 6 contacts and swivels the bell crank mechanism 14, with consequent movement of the spring toggle mechanism 13, the connecting rod 1 5 and a switch rail 26 to which connecting rod 1 5 is fixed. After switching the points, the lever 1 9 is returned to its initial horizontal position, flush with the top plate 12 and, as can be seen from Figure 4, below the level of adjacent rail 27. Claims

1. A lever box in which a manually operable lever is mounted in a pivot situated within the box.

2. A lever box as claimed in claim 1, substantially as described with reference to the drawings.