RAILWAY MAINTENANCE AND REPAIR VEHICLE
This invention relates to the maintenance and repair of railway or railroad tracks.
Operations such as the drilling of wooden sleepers are conventionally performed either by portable equipment or by large heavy vehicles which have the appropriate equipment mounted on them. Portable equipment has the disadvantage that its size and weight restrictions make it suitable only for relatively small jobs which do not require it to be carried large distances. The vehicles which are used, being large and heavy, have the disadvantage that they require a locomotive to propel them along the track and it is extremely difficult to remove them f om the track, for example to permit trains to pass over the track.
The object of the present invention is to provide a form of vehicle which overcomes these disadvantages. According to the invention there is provided a vehicle for use in the maintenance and repair of railway or railroad tracks which is in the form of a trolley comprising a chassis having wheels or rollers for engagement with the rails of a track and mounting means for a piece of equipment for performing an operation on the track. Being in the form of a trolley the vehicle is relatively light in weight so that it can be lifted on to and off a track by one or more persons and it can therefore be used in locations where work has to be stopped to allow trains to pass over the track, the trolley simply being lifted off the track and then replaced. Nevertheless the trolley can be made sufficiently strong to support portable equipment such as a sleeper drilling machine, a ballast tamping machine or a screw-driving machine with the advantage that the trolley can move the equipment substantial distances. The trolley can be of a simple construction.
Preferably the said mounting means is arranged so that, in use, the weight of a piece of equipment mounted thereon is supported directly by one of the rails on which the vehicle is placed. The chassis is preferably capable of being collapsed or disassembled. Preferably the wheels or rollers are of an electrically non-conducting material.
In a preferred embodiment the trolley chassis comprises a rigid support provided with wheels or rollers arranged to engage one of the rails of a track, the said mounting means being provided on this support so that, in use, the equipment is supported wholly by the support at a position above said rail, and a stabilising means carrying at least one wheel or roller for engagement with the other rail. With this arrangement the weight of the equipment is supported by only one of the rails and the stabilising means merely acts to steady the trolley, the trolley having an at least three point contact with the track.
The stabilising means may simply comprise a cross member, for example a rod, extending laterally from the rigid support and carrying a wheel or roller at its outer end. The cross member is preferably detachably connected to the support so that the trolley can be disassembled for storage and transportation. Conveniently the cross member is connectible to both sides of the support so that, in use, a piece of equipment mounted on the chassis can be positioned selectively on one or the other side of a railway or railroad track.
The mounting means for the equipment may comprise an articulated parallelogram mounted on the trolley and provided with balancing means arranged to provide a counterbalance for the weight of a piece of equipment mounted thereon so that, in use, the equipment is easily movable between operative and inoperative positions. The balancing means may be a gas piston and cylinder unit operatively connected between two opposed links of the parallelogram.
The invention will now be described, by way of example, with
reference to the accompanying drawings, in which:-
FIGURE 1 is a plan view of a preferred form of trolley according to the invention,
FIGURE 2 is a side view of the trolley, and FIGURE 3 is an end view of the trolley.
The drawings show a vehicle in the form of a trolley for use in the maintenance and repair of railway or railroad tracks, which has a chassis 1. This chassis comprises a rigid support member 2 having two wheels 3 rotatably mounted adjacent its respective ends for engagement with one of the running rails of a track. These wheels are made of an electrically insulating plastics material and are each formed with outer flanges 3 a arranged to keep the wheel on the rail.
A rod 4 extends into a hole formed in the support member 2 and is detachably secured to the member by a releasable fastening device. This rod extends laterally from the member and carries at its outer end a roller 5 for engagement with the other rail of the track. The roller is of plain cylindrical form and made of an electrically insulating plastics material so that, like the rod, it is light in weight. The rod 4 and roller 5 simply act as a stabiliser to maintain the trolley in a horizontal position when in use. The rod 4 can be inserted from both sides into the hole in the support member 2 and secured to the member so that an operator can conveniently choose which of the two rails of a track is to be engaged by the wheels of the support member. In a modification the rod, or a part thereof, may be disposed at a higher level than the plane containing the axles of the wheels 3 so that it clears any obstructions between the running rails such as guard/check rails. Where at least the outer end of the rod is higher, the roller 5 will be of a larger diameter.
The equipment for performing an operation on the track is supported wholly by the rigid support member 2. For this purpose the support member is
provided adjacent one end with an upstanding pillar 6 which supports one of the links 7 of a parallelogram linkage, the other links being designated 8,9 and 10. The link 7 is disposed vertically and is turnable about a vertical axis relative to the pillar 6, a ball bearing joint being provided between them, and the links are pivotally connected together by ball bearing joints.
The link 8 lying opposite the link 7 has a mounting 11 with a vertical pivot provided by a ball bearing joint for the equipment. In the example shown the equipment is a drill 12 for drilling holes in the wooden sleepers of a track. The drill comprises a support 13 carrying a drive motor 14 connected through gearing to a holder 15 for a drill bit. The support 13 is removably connected to the mounting 11.
A gas piston and cylinder unit 16 is connected between the links 7 and 8, the ends of the piston and the cylinder being pivotally connected to the respective links. The unit is arranged to counterbalance the weight of the drill so that it is easily movable up and down between a raised, inoperative position and a lowered, drilling position. The drill can also be turned about its vertical pivot on the mounting 11 and the parallelogram linkage 7,8,9,10 can be pivoted about the pillar 6 to swing the drill between a position above the support member 2 and a position above the track for drilling holes in the track sleepers The parallelogram linkage ensures that the drill moves up and down in a straight path so that the drill bit moves in a direction along its own axis, thereby ensuring the accuracy of the drilling operation. The gas piston and cylinder unit 16 is so positioned that it is not exposed to undesired shocks and it can easily be replaced. The trolley is provided with a simple brake or wheel locking arrangement (not shown) to prevent movement of the trolley whilst work is performed on the track.
The invention provides a trolley which is of a simple, compact and
lightweight construction. It can be used by a single operator and dismantled into two parts (by detaching the rod 4 from the support member 2) for storage and transportation. Hand grips 17,18 are provided, respectively, on the link 9 of the parallelogram linkage and the rod 4 to enable the trolley to be easily and quickly lifted on and off a track, for example to enable a normally running train to pass, these hand grips being so positioned in relation to the centre of gravity of the trolley that the trolley assumes a balanced, generally horizontal position when lifted by an operator.
As the wheels 3 and the roller 5 are of a plastics material the trolley is completely electrically insulated from the track. In particular, there is no path for electricity to flow through the trolley between the running rails of the track or through one of the wheels or the roller between the opposed ends of two adjacent lengths of a rail joined by an insulated fishplate, which could interfere with the track signalling.