GB2203601A - Connecting control units for electro-hydraulic control systems for mining equipment - Google Patents

Abstract

An electro-hydraulic control system for a mine working employs individual control units (1) fixed to roof supports for example. Each control unit has a housing (2) containing programmable electronic devices and is connected via cables (15, 15') to electromagnetic valves and possibly to a programmer. A connector (3) is coupled to the housing (2) and connects the housing (2) to a set of cables (21) leading to the input side of the control system. The housing (2) has a series of plug pins (17) which locate inside sockets (19) in the connector thereby to be connected to plugs (20) on the cables (21). The housing (2) can be removed from the connector (3) for access or change while leaving the connector (3) and input cables (21) intact. <IMAGE>

Description

IMPROVEMENTS IN CONTROL UNITS FOR ELECTRO-HYDRAULIC CONTROL SYSTEMS FOR MINING EQUIPMENT The present invention relates in general to electrohydraulic control systems for mineral mining equipment and more particularly to a control unit thereof.

In known electro-hydraulic control systems each roof support along a mine working is provided with an individual electronic control unit which contains, in a protected position in a stable housing, electronic devices particularly micro-processors forming part of a computer controlled system. Input and output sub-housings for the connection of the electrical input and output lines respectively are then detachably affixed to the two opposite sides of the main housing of the control unit.

In practice, the electronic control unit not only differs in its hardware and possible applications from one manufacturer to another, but different models with a different number of electrical connections are produced1 according to the required number of control functions, by one and the same manufacturer. Without major constructional conversion it is hardly possible to add to or modify the individual control unit or to change from the control system of one manufacturer to that of another.

A further drawback of the known control units resides in the difficulty of access. To carry out repairs on the individual electronic control units, for example, the input and the output sub-housings rigidly connected thereto have to be dismantled. Above all, access to the input sub-housings occupying a concealed position behind the individual control units and fitted with flexible cables is in general particularly difficult.

A general object of the invention is to provide an improved control unit.

In accordance with the invention a control unit for an electro-hydraulic mine control system has a main housing component containing at least one progammable electronic device and a connection component detachably mounted to the main component with plug and socket connections and serving to form an interface between electrical cables and the main component.

The control unit can be incorporated into the general structure and is characterized by a particularly compact design as well as by the ease with which it can be assembled and dismantled in the mine working. The unit is usable for control systems with a different number of functional parts to be actuated or which can be adapted or modified from this point of view when required with comparative ease.

The connection component can take the form of a connection bar with bores or sockets therein. The main housing block of the control unit is then connected to the connect bar via plug pin-and-socket connections and the connection bar also receives plug connections on a set of electric cables. In a preferred form, the control unit comprises a housing containing at least one programmable electronic device, connectors on the exterior of the housing for establishing connection with cables leading to electro-magnetic valve devices, plug pins on the housing leading to the connectors and/or the electronic device, means for facilitating programming of said electronic device, via a keyboard and a separate component detachably secured to the housing, the separate component having sockets receiving the plug pins and also plugs of further cables which make electrical connection with the plug pins.

The component or socket bar provides both a mechanical connection and also an electrical connection for the associated electronic device control housing. The simple connection bar can be equipped with as many connection devices as desired. When necessary the bar can be separated from the housing without having to release the electrical connections between the cables on the connection bar. The connection bar and the associated plug and socket connections therefore enables the control unit or its individual electronic control means housing to be simply and rapidly mounted and dismantled and subsequent alteration or extensions to the electronic control system for additional control functions can be effected without excessive labour.

Normally the control unit is mounted to some structure such as a roof bar of a roof support. The unit is preferably so arranged that the connection bar is situated on the rear of the housing, so that the latter can be pulled off the connection bar from the front. If the control unit is positioned on the underside of the roof bar it can be drawn up in the direction of the working, i.e. towards the mineral, e.g. coal face. The connection bar is preferably provided with connection means to enable it to be secured to the support structure and preferably to the underside of the roof bar. In this manner the connection bar with its connected cables remains firmly in its correct position even when the housing is removed for modification or some other purpose.

It is advisable for the housing to have a similar component in the form of a plug bar, via which the electrical connections are provided. The plug bar can be detachably or permanently affixed to the housing. The plug bar and also the connection or socket bar can be so constructed that they can be used to cope with the largest possible number of electrical connections and there can thus be a measure of redundancy. This arrangement makes it possible fdr the control system to be extended later without any special difficulty if further control functions are to be added. If necessary, the electronic control system of one manufacturer or the individual control units can be readapted, in a comparatively simple manner, to that of another manufacturer.The individual electronic control housing is also easily accessible, so that repairs can be effected without any problems.

The connection or socket bar and the corresponding plug bar are preferably provided with supporting and centering pins and apertures which inter-engage when the control housing is connected to the connection bar.

In a further advantageous embodiment of the invention the connection bar is provided with continuous bores forming the sockets into which plugs provided on the end of the electric cables can be plugged from one side while the plug pins or connection sleeves provided on the housing or on the plug bar thereof engage in the sockets from the other side, The mutually-engaged plugs and connection sleeves are provided internally with electrical contact elements such as contact pins, contact bushings or the like. The plug bar may likewise be provided with continuous borings which serve to accommodate the connection sleeves projecting beyond the end face of the plug bar. The borings are preferably of stepped construction, so that the connection sleeves are secured in the borings so as to be largely immovable in the axial direction. The external diameter of the connection sleeves can be approximately equal to the internal diameter of the sockets of the connection bar, so that the sleeves are securely held in the sockets and can at the same time serve as parts of the mechanical connection between the control housing and the connection bar.

It is also advisable that the control housing be likewise connected mechanically with the roof bar of the support or the like and-preferably in such a way that the mechanical connection is automatically released when the control housing is removed. This can be achieved by means of bolts, pins or the like, which engage borings and which are positioned on the mutually opposite side faces of the housing.

On that side of the housing which is situated opposite the connection bar and preferably on the front of the housing the connections for the electro-magnetic valve devices under control of the unit and/or electric cables leading to a programmer can be provided. On the other hand, however, the programmer can also be mounted permanently or detachably with its operating keyboard on the front of the housing. In this case it is advisable for all the electrical connections for the electric cables, including the cable leading to the valve devices to be provided on the rear connection bar.

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

Embodiments of the invention will now be described, by way of examples only, with reference to the accompanying drawings, wherein: Fig. 1 is a schematic, perspective, exploded view of a control unit constructed in accordance with the invention; Fig. 2 is a schematic side view of the unit in an operating environment and with the main components thereof disconnected from one another; Fig. 3 is a side view corresponding to Fig. 2 and showing the components connected together; Fig. 4 is a part-sectional schematic plan view of the control unit with other optional parts; Fig. 5 is an end view of one of the components of the unit shown in Fig. 4, the view being taken along the line V-V of Fig. 4; Fig. 6 is an enlarged cross-sectional view of one of the plug connections of the unit shown in Figs. 4 and 5;; Fig. 7 is a schematic front end view of the main block of the unit shown in Figs. 1 to 6; Fig. 8 is a schematic representation of the control unit with ancilliary parts of a control system in its operating environment; and Fig. 9 is a representation corresponding to Fig. 8 but showing a modified system.

As shown in Figs. 1 to 7, a control unit 1 for use in an electro-hydraulic control system for mining equipment is composed of two separate components, namely a main component 2 containing one or more programmable electronic devices such as a microprocessor and a connection component or bar 3. As described in more detail hereinafter, the bar 3 establishes electrical connection between electrical cables 21 with plugs 20 and further cables 15' with plugs 34 via the electronic circuitry in the component 2 to cause hydraulic valve devices to open and close in accordance with a programmed sequence of operations. The component 2 itself has a complementary rear connector bar 4 with projecting flanges 11 presenting plug pins 17 which mate with sockets 19 in the bar 3.

These sockets 19 also receive the plugs 20. The unit 1 is used in conjunction with a programmer 5 (Figs. 8 and 9) equipped with a keypad or keyboard which can alter the function or sequence of operations controlled by the electronic circuitry in the component 2. The programmer 5 can be connected with an input cable 6 to the component 2 as shown in Fig. 8 or detachably or permanently fitted to a front end panel 7 of the component 2, i.e. without the cable link, as shown in Fig. 9.

The component 2 is in the form of a flat box-like housing structure 8 which contains the electronic control circuitry to which the plug bar 4 is secured with screws.

The top of the housing 8 is closed with a removable cover 10 secured with screws 9 which can be removed to permit access.

The housing 8 has dimensions such that it can accommodate electronic devices from different manufacturers. The front panel 7 of the housing 8 is provided with electrical connectors 12, 13. The electric cables 15' with the plugs 34 at their ends engage with the individual connectors 12. These cables form outputs from the unit 1 and lead to the electro-magnetic valve devices for the various appliances to be controlled. Thus as shown in Figs. 8 and 9 a valve block 14 containing several of these valve devices is mounted to some structure, such as a roof support, and a bundle 15 of the cables 15' leads to the connectors 12. The valve devices serve to control the flow of pressure fluid to the various appliances of the installation. As also shown in Fig. 8 the programmer 5 can connect via the input cable 6 to the component 2 by way of the connector 13.The number of connectors 12 is such that an adequate number of appliances can be controlled with one cable 15' (Fig. 2 and 3) for each control line.

The plug bar 4 on the housing 8 has two rows of stepped bores 16 (Fig. 4) extending therethrough one above the other corresponding to rows of the sockets 19 in the connection bar 3. The bores 16 receive sleeves which form the plug pins 17 and project beyond the outer rear face 18 of the plug bar 4 to establish connection in both mechanical and electrical senses between the connection or socket bar 3 and the component 2. The socket bar 3 has through bores forming the sockets 19 which receive the plug pins 17. The plugs 20 on the ends of the electrical cables 21 also locate in the sockets 19 but from the face remote from the component 2. The cables 21 typically lead to a central control station for the electro-hydraulic system, to an electrical supply and also to adjacent roof supports and/or similar control units.

During assembly, the component 2 is presented to the bar 3 as shown in Figs. 2 and 3 to locate the plug pins 17 in the sockets 19. To facilitate the fitting operation, the bar 3 has pins 26 which engage in bores 25 in the bar 4 to centralize the components 3, 2. The bar components 3, 4 can be locked together in a detachable manner with the aid of screws 40 which pass through bores 41 in the flanges of the bar 4 and engage in threaded bores 42 in the bar 3. This modification is shown in Fig. 4. The screws 40 can be tightened up to draw the bar components 3, 4 together and establish a reliable connection. The sleeves or plug pins 17 provide electrical connection between the cables 21 and the electronic circuitry within the housing 8 and the connectors 12.The sleeves 17 have an external diameter generally matching the diameter of the sockets 19 and the plugs 20 have tapered ends which fit into the sleeves 17 and close contacts 17', 20' in these parts. Electrical plug connections of this kind are known as from German Utility Model 8435743.6. It is desirable to connect the plugs 20 to the bar 3 in a manner to resist traction forces and this can be achieved by providing U-shaped-coupling pieces or clamps 22 which are inserted into transverse bores 23 in the bar 3 to intersect the peripheries of sockets 19. The plugs 20 have grooves 24 which receive the limbs of the coupling pieces 22. To seal the sockets 19, O-rings 43 are preferably located in annular grooves in the sockets 19.

Further O-rings 44 are provided on the plug pins 17. To facilitate the separation of the bars 3, 4 for disassembly, compression springs 45 (Fig. 4) can seat on shallow recesses in the mating faces of the bars 3, 4.

The sockets 19 are preferably provided with one or more further bores acting as atmospheric vents. The screws 40 and the springs 45 can possible by omitted where such vents 46 are provided since no partical vacuum will be produced in the sockets19 when the pins 17 are withdrawn.

Conveniently, the vent bores are produced by means of a single transverse boring 46 which insects at least all the sockets 19 in one row and leads to the exterior. A valve 47 can be provided at the end of this boring 46.

The bar 3 and the block 2 are associated with or provided with connection means enabling these components to be secured to some structure such as the roof bar of a roof support. As shown in Fig. 5, the connection means for the bar 3 can take the form of screws 28 which engage through bores 29 in the bar 3 and mate with threaded holes at the lower face of the roof bar 27. In the case of the component 2, attachments 30 shown in Figs. 1, 4 and 7 are fixed to the end faces of the housing 8 and have bores 31 therein. Support members 32 are fitted to the lower face of the roof bar 27 and present spigots 33 which engage in the bores 31. U-shaped locking members 48 engage in transverse bores 35 in the attachments 30 and lock in grooves 36 in the spigots 33. During assembly, the bar 3 is fixed in position initially with the plugs 20 engaged in the sockets 19.The component 2 is then moved in the direction of arrow 84 in Fig. 2 towards the installed bar 3. The screws 40, if provided, can then be tightened to bring the centering pins 26 into the bores 25 and the plug pins 17 into the sockets 19 to produce the desired mechanical and electrical connection. When the component 2 is installed in this way the spigots 33 also engage in the bores 31 in the attachments 30 and the locking members 48 can be installed to secure the component 2 in place.

The various cables 6, 15' can be united with their plugs 34 (Fig. 4) in the sockets 12, 13 on the front panel 7.

To dismantle the unit, the plugs 34 are removed from the panel 7 and the locking members 48 and the screws 40, if provided, released to enable the component 2 to be removed from the front.

As shown in Fig. 6, the plugs 20 on the cables 21 are provided with notches 37. These notches 37 locate coding pins 38 which ensure the plugs 20 are correctly orientated in the sockets 19 to mate with the pins 17.

The housing 8 is standardized with the same layout of external interfaces at the front 7 and the rear 11 so that no conversion operations are necessary if the electronic components in the housing 8 are changed or added to. The number of connectors and plugs and sockets are sufficient to meet all the usual needs even if not all of these are utilized.

In the arrangement shown in Fig. 9, the programmer 5 or at least its keyboard is directly mounted on the front panel 7 of the housing 8 and all the interface connections are provided at the rear 11. The cable 15 leading the valve devices is connected via the electronic circuitry to the cables 21 on the one interface. The valve devices in the valve block 14 are actuated via the cable 15 and preferably two conductors of the cable 15 serve to supply electrical current to the valve devices while a bus bar 50 is provided in the block 14.

Claims (18)

1. In or for an electro-hydraulic control system for mining equipment; a control unit composed of a housing containing at least one programmable electronic device, connectors on the exterior of the housing for establishing connection with cables leading to electro-magnetic valve devices, plug pins on the housing leading to the connectors and/or the electronic device, means for facilitating programming of said electronic device via a keyboard, and a separate component detachably secured to the housing, the separate component having sockets receiving the plug pins and also plugs of further cables which make electrical connection with the plug pins.

2. A unit according to claim 1, wherein the connectors are provided on an interface in the form of a front panel of the housing and the means for facilitating programming comprises a programmer linked via a cable to another connector on the front panel.

3. A unit according to claim 2, wherein the plug pins are provided on another interface opposite the front panel.

4. A unit according to claim 1, wherein the means for facilitating programming is a programmer fitted to a front panel of the housing and the plug pins and the connectors are provided on an interface of the housing at a rear of the housing remote from the front panel.

5. A unit according to any one of claims 1 to 4, wherein connection means is provided to connect the component to a support structure.

6. A unit according to claim 5, wherein attachments are provided on the housing for location with fixings on the support structure to facilitate connection of the housing and the component.

7. A unit according to any one of claims 1 to 6, wherein the component is in the form of a bar and the housing has a complementary bar with the plug pins thereon.

8. A unit according to any one of claims 1 to 7, wherein means is provided for locating the housing and the component relative to one another for connection of the plug pins and the sockets.

9. A unit according to any one of claims 1 to 8, wherein the component has transverse bores intersecting the sockets which receive clamps for securing the plugs therein.

10. A unit according to any one of claims 1 to 9, wherein means is provided for detachably fixing the housing and the component together and for drawing the housing and the component together.

11. A unit according to claim 10, wherein springs are provided between the component and the housing to facilitate separation therebetween.

12. A unit according to any one of claims 1 to 11, wherein the sockets and the plug pins are provided with 0rings.

13. A unit according to any one of claims 1 to 12, wherein the sockets are ventilated with at least one bore acting as an atmospheric vent.

14. A control unit for an electro-hydraulic mine control system comprising a main housing component containing at least one programmable electronic device and a connection component detachably mounted to the main component with plug and socket connectors and serving to form an interface between electrical cables and the main component.

15. A control unit according to claim 14, wherein the main housing component and the connection component are each detachably secured to the underside of a roof bar and the main housing has a front panel to which a programmer is mounted or connected and a rear panel with which the connection component 'is connected.

16. A control unit according to claim 15, wherein the connection component is provided with sockets for receiving plug pins on the rear panel of the main housing on one face and plugs on the cables on an opposite face and there is provided contact means for establishing electrical contact between the plugs and the plug pins.

17. A control unit according to claim 16 and further comprising additional connectors for connection via cables to electro-magnectic valves.

18. A control unit substantially as described with reference to, and as illustrated in, any one or more of the Figures of the accompanying drawings.