GB2044323A - Ballast Packing Apparatus - Google Patents

Abstract

The apparatus is mounted on a railway vehicle and comprises a carriage (37) vertically movable in guides (35a etc) and carrying tines (40, 41). The tines are pivotally mounted on shafts (43, 44) for pivotal movement towards each other to pack ballast about a railway sleeper. The tines have extensions (45, 46), between which is connected a hydraulic ram (50) for effecting a ballast packing operation. The hydraulic ram is floating so as to allow for misalignment of the tines relative to the sleeper. <IMAGE>

Description

SPECIFICATION Ballast Packing Apparatus This invention is concerned with railway ballast packing apparatus for use in packing ballast around railway sleepers.

It is known to provide such apparatus, which is mounted on a vehicle which runs on rails mounted on the sleepers around which the ballast is to be packed. The apparatus includes vertically adjustable support legs for supporting the vehicle and means for clamping the rails whilst a packing operation is carried out. A tool or grapple tine carrier is mounted for vertical adjustment on the vehicle for inserting packing tools into ballast on opposite sides of a sleeper. These tools are then brought towards each other and the sleeper to effect packing. Hydraulic cylinders are used to move the tools towards each other and to move the carriage vertically. A cylinder is directly connected between the body of the apparatus and the carriage to move the latter vertically.

During initial movement of the carriage downwardly, the tools move through air without resistance. Once the tools have struck the ballast, an increasing resistance has to be met as the tools penetrate the ballast. The present invention permits rapid movement of the tools through air, the speed decreasing as the tools penetrate the ballast, so that the maximim force is exerted substantially at maximum penetration. This arrangement permits a packing operation to be carried out more quickly than with a conventional apparatus.

The present invention provides ballast packing apparatus mounted on a railway vehicle and including a body, a carriage vertically reciprocable on the body, ballast packing tools mounted on the carriage, a prime mover mounted on the body, and a linkage connected between the prime mover and the carriage and arranged so that the carriage is advanced downwardly by the prime mover through the linkage the ratio of the incremental distance moved by the carriage to the corresponding incremental distance moved by the prime mover reduces.

Preferably, the prime mover is a piston-cylinder unit mounted horizontally between opposite first and second pivots of a parallelogrammic linkage, a third pivot of linkage being mounted on the body and supporting the piston-cylinder unit and a fourth pivot of the linkage being connected to the carriage.

With this arrangement, the apparatus can be less high than known apparatus in which there is a vertically mounted piston-cylinder unit to operate the carriage. This permits a lowering of the centre of gravity of the apparatus with consequent improved stability.

Reference is now made to the accompanying drawings, wherein: Figure 1 is a side elevation of apparatus according to the invention; Figure 2 is a rear view of the apparatus; Figure 3 is a diagrammatic Illustldtlon of a parallelogrammic linkage of the apparatus; and Figure 4 shows a curve of penetration force of the tools plotted against extension of a pistoncylinder unit providing the force.

Referring to Figures 1 and 2, the apparatus shown is mounted on a railway vehicle having flanged wheels 11, 12, engaged with rails 13, 14.

The vehicle is self-driven by an engine 15 and incorporates a platform 16 on which is provided a seat 1 7 for an operator. Controls for driving the vehicle and operating the ballast packing apparatus are in reach of an operator sitting on the seat. Vertically extensible and retractable legs 20,21 are provided at an opposite sides of the vehicle for supporting the vehicle on the ground. Clamps 22 are provided for clamping the rails to the vehicle, whilst the legs are extended and whilst a ballast packing operation is carried out. In Figure 2, the left side of the drawing shows the leg 20 retracted and the right side shows the leg 21 extended.

Separate ballast packing apparatus 30 and 31 is provided at each side of the vehicle, both of the same construction. Only that numbered 30 is described hereafter. The two sets of apparatus are operable independently.

The body of the apparatus 30 is integral with the vehicle and includes a pair of vertical guides defined by pillars 35a, 35b and 36a, 36b respectively. A carriage 37 is vertically movable in the guides and includes blocks 38, 39 respectively slidable in the guides. The carriage includes lugs 70 (only one shown) by which the carriage is supported from the top of the guides by a pair of linkages 71 '(only one shown, the other linkage being hidden by that shown in Figure 1). Each linkage 71 is parallelogrammic and comprises four equal-length links pivoted end to end in a parallelogram. One pivotal connection is made to the lugs 70 at 72 and the opposite pivotal connection is made at 73 to a beam of the body. A first piston-cylinder unit 75 is connected between the other two pivotal connections 76, 77.Packing tools 40, 41 are mounted on the carriage 37.

Referring now to Figure 3, the linkage 71 is shown diagrammatically in two extreme positions. It can be seen that extension of the piston-cylinder unit 75 causes raising of the pivotal connection 72 and hence of the carriage and vice versa. By this arrangement during retraction of the piston cylinder unit 75, there is initially a large downward movement of the carriage for a given incremental retraction, as compared with a small downward movement for the same incremental retraction as the pivotal connection 72 approaches the low position shown in Figure 3. Accordingly, there is initially rapid movement of the carriage with low force and, as the packing tools begin to penetrate the ballast in use, the movement is much slower with much greater force. This is shown graphically in Figure 4.

The packing tools 40, 41 are arranged in two parallel banks. As in apparent from Figure 2, the tools in each bank are arranged in pairs, such as 40a, 40b, one pair at each side of the rail 14. The tools are usually known as grapple tines. Each bank of tools is pivotally mounted by means of horizontally extending shafts 43, 44 respectively for pivotal movement towards the other bank of tools. The shafts 43, 44 are joined together by tie-bars such as 57 and each shaft is mounted in rubber bearings 55, 56. The tools have extensions such as 45, 46 above the shafts 43, 44 and these extensions are pivoted to a second piston-cylinder unit 50.One bank of tool extensions is pivotally connected to the cylinder 50a and the bank of tool extensions is pivotally connected to the piston 50b, so that the unit is floating.

In use, the tools are embedded in ballast, by lowering of the carriage 37 in the manner described above, with one bank of tools at one side of a sleeper 80 (Figure 1) and the other bank of tools at the other side of the sleeper. The second pistoncylinder unit is then extended to cause the two banks of tools to pivot towards each other with accompanying packing of the ballast about the sleeper 80. Should the carriage 37 not be positioned centrally with respect to the sleeper 80, or if the ballast is unevenly distributed, when one bank of tools has packed the ballast to its maximum extent, the other bank of tools will continue to move with accompanying sideways movement of the piston-cylinder unit 50. This avoids excess force being exerted by one of the banks of tools, which might damage the sleeper.

The rubber bearings 55, 56 are pre-stretched and permit some movement of the shafts 43,44.

The tie-bars 47 prevent any horizontal relative movement between the shafts, but relative vertical movement of the shafts is permitted. This provides automatic adjustment for discrepancies in ballast density (or level) during penetration of the tools. The release of energy stored by the bearings, due to the tools passing through a less dense zone, also aids penetration as the tools reenter a more dense zone.

Claims (4)

Claims

1. Ballast packing apparatus mounted on a railway vehicle and including a body, a carriage vertically reciprocable on the body, at least a pair of ballast packing tools pivotally mounted on the carriage for pivotal movement towards each other to pack ballast about a sleeper in use, and powerextensible means connected between the tools and capable of floating movement relative to the body.

2. Ballast packing apparatus according to claim 1, wherein the carriage mounts two banks of tools each said pair of tools comprising a tool in each bank, a plurality of tools in each bank being carried by a common pivot shaft, the tools having extensions to which the power-extensible means is connected.

3. Ballast packing apparatus according to claim 2, wherein each shaft is mounted in resilient bearings to permit movement of the shafts therein.

4. Ballast packing apparatus according to claim 3, including a tie-bar between the shafts to prevent relative horizontal movement of the shafts.