GB2077339A

GB2077339A - Improvements in the control of hydraulic equipment in mineral mining

Info

Publication number: GB2077339A
Application number: GB8114131A
Authority: GB
Original assignee: Gewerkschaft Eisenhutte Westfalia GmbH
Current assignee: Gewerkschaft Eisenhutte Westfalia GmbH
Priority date: 1980-05-10
Filing date: 1981-05-08
Publication date: 1981-12-16
Also published as: ZA813112B; JPS576099A; GB2077339B; FR2482188B1; DE3017993A1; FR2482188A1; AU7026281A

Abstract

A roof support with hydraulic props 11 mounted between floor and roof engaging structures 10, 12 has a lamp 19 beneath the roof structure 12 which serves to illuminate the mineral face of a working in which the support is installed. An electronic control device 22, forming part of a control system which initiates a sequence of automatic operations by actuating electromagnetic valves, is combined with the lamp 19 and is connected to an electric power supply at an intrinsically safe low level. <IMAGE>

Description

SPECIFICATION Improvements in the control of hydraulic equipment in mineral mining The present invention relates in general to a control system for controlling the operation of mining equipment in an underground mine working.

For the control of hydraulic appliances, e.g.

props and rams, in mining equipment it is known to use a system which responds to command signals, usually generated remotely at a control station in a roadway or at one end of a mineral face. The control system then causes an automatic sequence of operations to occur, such as for example retraction of the proprs of each of a group of roof supports, shifting the supports in turn, extending and setting the props after shifting and finally advancing the conveyor. The individual roof supports are usually provided with control units containing valves and control devices pertaining to the control system. Such devices can provide for an automatic sequence of operations to occur on a group of supports as well as manual local control of the support itself. Safety can be ensured by only permitting local control once an appropriate enable command signal has emanated from the control station.The use of electronic control devices which provide local electrical control signals at an intrinsically safe low power level to operate electromagnetic valves enables easily programmable stored sequences of operations to be built in. This, in conjunction with proximity devices sensing the position of a plough or other winning machine, enables the entire mineral winning operation to be monitored and controlled from the control station.

A general object of the present invention is to provide an improved roof support which can be used in the aforementioned type of control system.

A support constructed in accordance with the invention has a lamp combined as a common constructional assembly with an electronic control device serving as part of a control system for the controlling of the operation of hydraulically operated appliances, e.g. props and rams, of the support.

The invention also provides a control system for controlling the operation of mining equipment in an underground mine working; said system comprising electronic control devices which provide local electrical signals at an intrinsically safe power level for initiating said operations in response to command signals generated at a control station; wherein the control devices are mounted on the lamps of roof supports.

It is quite common to provide lamps on the individual roof supports of a mine working to illuminate the mineral face. Conventional lamps have compact and stable housings sealed against fire damp and provided with ducts and cable connections. In accordance with the invention an electronic control device is combined with the lamp of a roof support. In one constructional version the control device is located inside the lamp housing. In this case it is possible to provide a separate chamber or compartment in the lamp housing to accommodate the device. In another embodiment however the control device is provided with its own housing which is externally fitted to the lamp housing to form a constructional assembly therewith. Whether the control device is positioned in, or on, the lamp housing, the electric power to drive the device can be derived from the electrical supply for the lamp.This can involve linking an electrical supply cable to the lamps and to the devices so that no separate additional supply is needed to power the devices.

In mine workings where there is danger from fire damp the electrical power for operating the lamps must be at an intrinsically safe low level and it follows that the control devices are similarly protected. Although the lower power electrical supply can be provided inherently so that the electrical supply cable only conveys low power, this can cause problems with long conductors where energy losses become significant. To avoid this problem at least one of the lamp housings can contain a converter which converts higher power supplied by the common cable to low power for energizing the light source(s) and the device(s).

Each support would normally also have a control unit or block with conventional valves as well as manually-operable switches and electromagnetic valves controlled by the electronic control device and connected thereto with the aid of an electrical cable. The selection of a stored program or initiation of local control can be effected at this unit easily accessible from the working. It is also possible to have sequence control switches, stored programs and further monitoring or switching means combined with the electronic control device.

The invention may be understood more readily and various other features of the invention may become apparent, from consideration of the following description.

An embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawing which is a perspective view of a support constructed in accordance with the invention.

As shown in the drawing, a support constructed in accordance with the invention is composed of a floor-engaging sill structure 10, a roof-engaging structure 12 and hydraulic props 11 disposed between these structures 10, 12. Each structure 10, 12 can be of single or multipart construction and the props 11 are mounted to the structures 10, 1 2 for pivotal and preferably universal movement as by ball-and-socket joints. The structure 12 is provided with an advance lining in the form of a pivotable roof bar 13 which projects towards a mineral face and which can be raised and Idwered with the aid of a hydraulic piston and cylinder unit 14.A goaf shield 1 5 is pivotably connected to the rear of the structure 12 as indicated by pivot joint 1 6. the shield 1 5 screens off the support from the goaf or stowage zone and is linked to the floor structure 10 via guide rods 17, 1 8. The overall arrangement forms the socalled "lemniscate" guide which permits the shield 1 5 to follow the extension and retraction of the props 11.

A lamp 19 is disposed in known manner between the props 11 at the mineral face end of the support and suspended beneath the roofengaging structure 12. As indicated by arrows the lamp 19 serves to illuminate the mineral face. The lamp 19 has a fire-damp proof housing 20 containing a light source which is energized by a converter such as a transformer in the housing 20.

In a typical mine working a series of supports as described and illustrated would be positioned sideby-side. The electric power supply for the lamps 19 can be derived from a common cable 21 connected to the lamps 1 9 and each lamp housing 20 can contain its own converter which provides electric power for the light source at an intrinsically safe power level. Alternatively, a number of lamps 1 9 can share a common converter in which case the cable linking these lamps 1 9 would only convey electric power at the low safe level. Another housing 22 contains an electronic control device for controlling the operation of the various hydraulic-fluid operated appliances.The device can provide electric control signals at an intrinsically safe low power level which actuate intrinsically safe electromagnetic valves which open and close hydraulic pressure fluid flow paths. The housing 22 is fixed to the lamp housing 19 but it is possible to form a common housing which contains the light source and perhaps its associated converter on the one hand and the electronic control device on the other hand. Conveniently separate chambers or compartments can house these components.

Whether the housings 22, 20 are separate or combined, the control device is fed with the low level power used to energize the light source.

It is advisable for all the supports to be controlled from a control station and hence the control devices in the housings 22 are all connected to a control line leading to this control station and conveying command signals. Each support also has a control unit 23 which has the necessary electromagnetic and fluid control valves. An electrical multi-core cable or line 24 connects the unit 23 to the control device in the housing 22. Each support can be controlled to perform a sequence of operations by feeding local control signals along the cable 24 to the unit 23.

The unit 23 can have a manually-operable switch or switches which can be altered to select a particular programme or sequence of operations as well as a manually-operable control valve allowing local control of the support. Stored programs can be provided in the unit 23 or with the device in the housing 22. Signals can thus pass along the cable 24 from the unit 23 to the device in the housing 22. The control unit 23 is connected to hydraulic pressure and return lines 25, 26 and conduits link the various hydraulic appliances to the unit.

Claims

1. A roof support for use in mineral mining which employs hydraulically-operated appliances and a lamp combined as a common constructiona assembly with an electronic control device serving as part of a control system for controlling the operation of said appliances.

2. A support according to claim 1, wherein the lamp and the electronic control device share a common housing.

3. A support according to claim 1, wherein the electronic control device is contained in a housing which is fixed to a further housing of the lamp.

4. A support according to any one of claims 1 to 3, wherein the lamp has a converter which converts electric power supplied from a cable to an intrinsically safe low level used for energizing both a light source of the lamp and the electronic control device.

5. A support according to any one of claims 1 to 3, wherein electric power at an intrinsically safe low level is supplied to the assembly by a cable to energize both a light source of the lamp and the electronic control device.

6. A support according to any one of claims 1 to 5, wherein there is further provided a control unit with electromagnetic and control valves for controlling the operation of said appliances, said unit being connected to said control device with the aid of a cable for carrying electrical control signals.

7. A support according to any one of claims 1 to 6, wherein there is further provided manuallyoperable switching means which selects a desired sequence of operations from a stored program controlled by the control device.

8. A support according to any one of claims 1 to 7, wherein the constructional assembly is mounted at the underside of a roof-engageable structure of the support.

9. A control system for controlling the operation of mining equipment in an underground mine working; said system comprising electronic control devices which provide local electrical signals at an intrinsically safe power level for initiating said operations in response to command signals generated at a control station; wherein the control devices are mounted on the lamps of roof supports.

10. A roof support substantially as described with reference to, and as illustrated in, the accompanying drawing.