Patent Application
20190283784
The present invention relates to the handling of rail wagon covers, in particular an automated system for uncovering and covering a rail wagon with a rigid cover at a bulk loading facility.
Traditionally in Australia coal rail wagons have had open tops when in transit. Consequently a considerable amount of dust is lost from such wagons and deposited along the train lines and adjoining properties. This is clearly undesirable due to the environmental impact of the coal dust. Moves are now afoot to introduce legislation to mandate the use of covers on coal wagons. As well as preventing product loss, covered wagons also prevent product contamination and protect against rain and snow.
A conventional approach to handling wagons covers at bulk loading facilities is to remove the cover before the loading facility, transport the cover around the facility and refit the cover once the wagon has been loaded. This requires a large area for temporary storage of covers and a convenient pathway around the loading facility.
Large mobile or fixed gantry cranes are used to remove and refit the cover, which require the wagons to be stationary. This approach is unsuitable for coal loading facilities as they are designed to operate with continuously moving wagons. It is not feasible to repeatedly stop and start a large coal train.
Alternative systems for removing and refitting wagon covers suitable for use with continuously moving wagons are disclosed in US patent publication U.S. Pat. No. 7,878,124 B2 and US patent application publication US 2016/0046304 A1. In these systems wagon covers are attached by hinges to a wagon and removed and replaced with either a system of helical tracks engaging the covers or an elaborate gantry system. Such systems require a considerable area before and after the loading facility which may not be available, and also require complicated hinging and latching arrangements to be fitted to each wagon and cover with their inherent cost and maintenance issues.
The object of this invention is to provide a system for removing and replacing rigid covers on rail wagons requiring minimal infrastructure and wagon componentry to alleviate the above problems, or at least provide the public with a useful alternative.
In a first aspect the invention provides system for removing and refitting rigid covers on rail wagons, comprising a gantry crane with a laterally moving trolley and a suspended spreader with means for engaging a rigid cover.
Preferably the spreader is suspended from the trolley by skewed cables and electromagnets attached to the spreader engage magnetically susceptible pads attached to the cover. The spreader may include side skirts for engaging the rigid cover.
In preference the gantry crane further comprises rubber drive wheels, may run on rails, or may be fixed in position and comprise a longitudinally moving bridge.
In preference the electromagnets actuate a locking mechanism to secure the covers to the wagons, and preferably the locking mechanism comprises a locking bar movable under a lip of the side of the wagon.
Preferably the locking mechanism further comprises first and second opposed cranks, and wherein vertical displacement of the magnetically susceptible pads results in a vertical movement of the locking bar, and wherein rotational movement of the magnetically susceptible pads results in a horizontal movement of the locking bar.
Preferably rotational movement of the magnetically susceptible pads is effected by energizing the electromagnet and vertical movement of the magnetically susceptible pads is effected by the weight of the spreader.
Preferably the wagon cover is formed of resilient material to accommodate vertical and rotational movement of the magnetically susceptible pads, and the electromagnets and the magnetically susceptible pads are disposed at a non-zero angle to each other. The side edge of the electromagnets is preferably aligned with the centre of the magnetically susceptible pads.
It should be noted that any one of the aspects mentioned above may include any of the features of any of the other aspects mentioned above and may include any of the features of any of the embodiments described below as appropriate.
Preferred features, embodiments and variations of the invention may be discerned from the following Detailed Description which provides sufficient information for those skilled in the art to perform the invention. The Detailed Description is not to be regarded as limiting the scope of the preceding Summary of the Invention in any way. The Detailed Description will make reference to a number of drawings as follows.
The drawings include the following integers:
The following detailed description of the invention refers to the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings and the following description to refer to the same and like parts. Dimensions of certain parts shown in the drawings may have been modified and/or exaggerated for the purposes of clarity or illustration.
The present invention provides a system for removing and refitting rigid covers on rail wagons gantry cranes to minimise infrastructure, and simple rigid covers for the wagons that don't require any elaborate hinging means. Preferably rubber tyred mobile gantries are used, however, rail mounted or fixed gantries are also anticipated by the invention. The gantry crane can match the speed of a moving wagon and deploy a spreader via skewed suspension ropes to engage the covers with the aid of electromagnets. The covers are lifted up, moved laterally and lowered again to hinge on the side of the wagons which are then loaded. Once loaded the reverse procedure replaces the covers. As part of the system a latch mechanism is provided for securing covers to wagons.
As the system for refitting covers is essentially the same as the system for removing covers, but operating in reverse, only the system for removing covers will be shown in the figures and discussed in detail. The system for refitting covers will be discussed in brief focussing on any differences to the system for removing covers.
The system for removing wagon covers is shown as 10 in
The rigid cover 40 as seen in
The gantry crane 60 is shown in
The trolley 70 includes four hoists (not shown) which control suspension ropes 72 from which the spreader 80 is suspended. The suspension ropes are skewed both longitudinally and laterally to minimise swaying of the spreader. The spreader comprises a planar body 81 and side skirts 82 for engaging with the side skirts 44 of a rigid wagon cover 40. The spreader also holds electromagnets 84 for engaging with the steel pads 48 on the wagon cover thus allowing the cover to be controllably raised and lowered.
The process of removing a cover from a wagon will be discussed with the aid of
The cover removing process is under the control of an automated control system located in the drive/control cabinet 65 which allows the gantry crane 60 to operate autonomously. The process is triggered by the detection of a wagon with the aid of an optical detector looking for the leading edge of a wagon 20. The wagons are fitted with RFID transponders which allow their identities to be read, from which the type of wagon and pertinent characteristics for use by the control system can be determined such as the height and width of the wagon and the position of the steel pads 48 used to engage with the electromagnets 84 of the spreader 80. Once a wagon has been detected and confirmed by the presence of an RF transponder the gantry crane will move from its parked position until it can longitudinally align the electromagnets 84 with the steel pads 84 and match the speed of the wagon with the aid of a speed sensor such as a back scattering Doppler radar. The control system uses the edge detection and measured speed of the wagon together with the known wagon parameters to produce an appropriate acceleration profile for the gantry and controls the gantry drive motors to achieve such.
As the gantry crane 60 matches the speed and position of the wagon 20 longitudinally as discussed above, the trolley 70 will move across the bridge 61 if needed to laterally align the electromagnets 84 with the steel pads 48. After the initial alignment the wagon 20 cover 40, trolley 70 and spreader 80 will be as per
Once the wagon has been filled and cleared the loading facility the cover is refitted by a second gantry crane. The cover refitting process is simply the reverse of the cover removing process, following the sequence shown in
The system has been shown and described using rubber tyred mobile gantry cranes, however other forms of gantry crane may also be used. In a second embodiment of the invention a rail mounted gantry crane is used. In this embodiment tracks for the gantry crane are laid either side of the tracks for the wagon. In a third embodiment of the invention a fixed gantry is used which allows for longitudinal movement of the gantry bridge. In applications where the rail wagons are not required to move continuously a still further embodiment is applicable in which the gantry crane does not move longitudinally, having the wagons shunted into position instead.
In the embodiments of the invention described so far the covers have been retained on the wagons by gravity alone, relying on the significant weight of the cover to resist displacement by wind or the air resistance inherently created by a moving train. In a further embodiment of the invention the cover is augmented by a latching mechanism to secure it to the wagon. The latching mechanism is activated by the already present electromagnets used to lift the covers.
A latching mechanism is shown in conjunction with cutaway views of a side of a wagon and a wagon cover in
To disengage the locking bar 124 from under the lip 112 both a vertical movement as shown in
In
In
To engage the latching mechanism 100 the electromagnet 130 is de-energised. Gravity will then be free to act on the locking bar 160, pulling it downwards, and due to the action of the cranks 150 and 155 move it horizontally until it sits under the wagon lip 112. Subsequent raising of the electromagnet will allow the various components to return to the positions shown in
The sequence of using electromagnets to latch and unlatch the cover is readily integrated into the cover removal and replacement process described in relation to
The movement of the various components relies on resilience of both the cover 120 and the tie bar 124. The resilient deformations are only of the order of a few millimetres in components that span several metres and can be handled by many different materials. The cover is preferably made from thermo-formed 3 mm polycarbonate corrugated sheets, allowing a cover for a 15 metre wagon to weigh approximately 150 kg and still be suitably rigid to allow for handling and suitably resilient to allow the locking mechanism to function. The tie bar and other components of the linkage mechanism can be made from mild steel.
Further downward vertical motion of the spreader, from the “just touching” condition of
In practise a 300 kg spreader sitting on wagon cover as described above will deform the cover such that the steel plates rotate by approximately 1.5%. Starting with a differential slope of roughly 3.5% this will leave a 2% slope. A steel pad of approximately 200 mm will give an airgap of approximately 2 mm and subsequent differential movement of the links of 4 mm. Once amplified by the cranks, which have arm lengths in the ratio of 1:10, the lock bar is displaced 40 mm horizontally when the electromagnet is energised or de-energised.
A system employing four commercially available electromagnets, each rated at 500 kgf will provide sufficient holding force to raise the combined weight of the spreader and cover (approximately 450 kg) and also provide sufficient force to operate over the 2 mm airgap to rotate the steel pad as in the transition from
The reader will now appreciate the present invention which provides a system for removing and replacing rigid covers on rail wagons requiring minimal infrastructure and wagon componentry. The use of skewed suspension ropes greatly reduces any sway or rotation of the cover as it is moved. Optional latches secure the cover for high wind situations.
Further advantages and improvements may very well be made to the present invention without deviating from its scope. Although the invention has been shown and described in what is conceived to be the most practical and preferred embodiment, it is recognized that departures may be made therefrom within the scope of the invention, which is not to be limited to the details disclosed herein but is to be accorded the full scope of the claims so as to embrace any and all equivalent devices and apparatus.
In the present specification and claims (if any), the word “comprising” and its derivatives including “comprises” and “comprise” include each of the stated integers but does not exclude the inclusion of one or more further integers.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2016901894 | May 2016 | AU | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/AU2017/050472 | 5/19/2017 | WO | 00 |
