WO2007029211A2

WO2007029211A2 - Skip and door opening arrangement therefor

Info

Publication number: WO2007029211A2
Application number: PCT/IB2006/053183
Authority: WO
Inventors: Berend Jan Werkman
Original assignee: Berend Jan Werkman
Priority date: 2005-09-09
Filing date: 2006-09-08
Publication date: 2007-03-15
Also published as: WO2007029211A3

Abstract

The invention provides a door opening arrangement, suitable for use in opening a door of a skip positioned in a discharge station, the door opening arrangement including an actuating assembly provided at the discharge station; the actuating assembly having a primary engagement mechanism being adapted releasably to engage an opening means connected to the door of the skip; the primary engagement mechanism being displaceable between a first position wherein the engagement mechanism is located adjacent the skip, and a second position wherein at least part of the primary engagement mechanism is displaced so as to displace the opening means, in so doing opening the door of the skip.

Description

SKIP AND DOOR OPENING ARRANGEMENT THEREFOR

FIELD OF THE INVENTION

The invention relates to a receptacle suitable for use in conveying ore in mining applications, and more particularly, but not exclusively, to a skip suitable for conveying particulate ore to a discharge station where a displaceable door opening arrangement is provided for opening a door of the skip.

BACKGROUND TO THE INVENTION

A skip is a generally elongate receptacle that is commonly used in mining applications to convey ore and/or broken rock inside a shaft of a mine. The skip is typically used to convey ore from a level where the ore is being mined to a required elevated level where the ore is required to be discharged, typically in the headgear of the mineshaft.

A skip comprises a hollow body that defines a normally downwardly extending loading chamber having a charge opening towards an operatively upper end of the body, and a discharge opening towards an operatively lower end of the body. The discharge opening is closed by way of a door, which can be selectively displaced between open and closed positions. The configuration of the skip allows for ore to be loaded and discharged under the force of gravity. The loading chamber is generally rectangular in cross-section, and the height of the body is usually at least double the transverse span of the body. The body furthermore includes a sloping bottom adjacent the discharge opening that aids in directing the ore towards the discharge opening upon discharge of the ore. In use the skip is suspended in a mine shaft by way of a winding cable that can be displaced in order to displace the skip up or down inside the mine shaft. Various configurations are provided where a second skip forms part of the same system, the second skip being configured to balance the first skip, and the second skip will therefore be at the bottom if the first skip is at the top and vice versa. This dual skip arrangement is such that one skip is charged whilst the other skip is being discharged. It would thus be appreciated that a delay in one of the actions, whether charging or discharging, will also result in a delay in the opposite action taking place at the other skip, thus adversely affecting the efficiency of the system as a whole.

When a skip has been charged with ore, the skip is hoisted to a discharge station, typically in the headgear of the mineshaft, where the door is opened and the ore is discharged into a suitable discharge arrangement. Many configurations are known wherein the door is automatically opened when the skip reaches a predetermined position in the discharge station.

In one common configuration, the skip is guided to travel upwards adjacent stationary tracks or tipping paths, in order for cam followers, suitably arranged on the door, to enter such tipping paths. The tipping paths are profiled to cause the cam followers to open the door when the skip is upwardly displaced relative to the stationary tipping paths. The time required to displace the skip once a lower part of the tipping path is reached adversely impacts on the total system efficiency, and it would be beneficial if such delay could be minimized, or preferably avoided altogether. In addition it would be possible to increase the total length of the skip if the skip does not have to travel through a tipping path. When stationary tipping paths are used, the door of the skip is closed while the skip is moving, which movement may result in disturbance of fine rock particles that stick to the interior surface of the skip, and subsequently may result in such fine rock particles being spilled through the discharge opening that is not fully closed yet.

A further skip design that is currently in use has a radial door that is opened by means of an onboard actuator, such as for example a pneumatic piston and cylinder arrangement that is mounted on the skip. This design allows the door of the skip to be openable without having to travel through a stationary tipping path, but has the disadvantage that the actuator takes up a lot of space on the skip. In addition, if the actuator is pneumatically operated, it must be connected to an air receiver that must also be mounted on the skip, thus taking up additional space and adding further weight. A still further disadvantage of such arrangement is that means must be provided for the system to be recharged with compressed air form an external source when the skip is positioned in the discharge station.

OBJECT OF THE INVENTION

It is accordingly an object of this invention to provide a skip, and in particular a door opening arrangement for a skip, which will at least partially alleviate the abovementioned disadvantages.

It is a further object of this invention to provide a skip and a door opening arrangement therefore, which will be a useful alternative to existing skips and door opening arrangements. SUMMARY OF THE INVENTION

In accordance with the invention there is provided a door opening arrangement, suitable for use in opening a door of a skip positioned in a discharge station, the door opening arrangement including: an actuating assembly provided at the discharge station; the actuating assembly having a primary engagement mechanism being adapted releasably to engage an opening means connected to the door of the skip; the primary engagement mechanism being displaceable between a first position wherein the engagement mechanism is located adjacent the skip, and a second position wherein at least part of the primary engagement mechanism is displaced so as to displace the opening means, in so doing opening the door of the skip.

There is provided for the door opening arrangement to be adapted in order for the skip to remain substantially stationary when the door is opened.

The primary engagement mechanism may include a track that is adapted to receive the opening means.

The primary engagement mechanism may be pivotably mounted, in order for the track to be pivotable between the first and the second positions. Alternatively, the primary engagement mechanism may be slideably mounted, in order for the track to be slideable between the first and the second positions. The track may be elongate, and may more particularly be of arcuate configuration. A concave side of the track may be directed towards the door of the skip. The track may be in the form of two substantially parallel elongate strips extending from a base plate.

There is also provided for the actuating assembly to include an actuator. The actuator may be hydraulically, pneumatically or electrically actuated. Preferably the actuator is in the form of a piston and cylinder assembly.

The actuator may be pivotably mounted at the discharge station, and may be pivotably connected to the primary engagement mechanism.

The opening means may be in the form of at least one extension that extends from the door, and may alternatively extend from a linking arm that is connected to the door.

Preferably the opening means terminates in a rotatable member. The rotatable member may be in the form of a roller.

There is provided for the primary engagement mechanism to define a cam surface upon which the opening means can be displaced, the roller of the opening means acting as a cam follower.

In an alternative embodiment there is also provided for the opening means to be in the form of a track located in the door, and for the primary engagement means to include a roller for engaging the track in the door. There is still further provided for the door opening arrangement to include a secondary engagement mechanism suitable for engaging an opening means located on a chute that is pivotably secured to the skip.

The secondary engagement mechanism may be in the form of a track, and is preferably in the form of a stationary track.

The secondary engagement mechanism is located below the primary engagement mechanism, and there is provided for the opening means located on the chute to engage the secondary engagement mechanism prior to the opening means connected to the door engaging the primary engagement mechanism.

According to a further aspect of the invention there is provided an actuating assembly, suitable for opening a door of a skip, the actuating assembly including: an actuator that is displaceable between first and second positions when actuated, and an elongate track connected to the actuator; the elongate track being displaceable by the actuator when the actuator is actuated.

Preferably the elongate track is pivotably mounted to a stationary surface at a discharge station, and is pivotably displaced by the actuator when actuated. According to a further aspect of the invention there is provided a method of opening a door of a skip, the method including the steps of: providing a door opening arrangement as described hereinbefore; displacing the skip relative to the primary engagement mechanism in order for the opening means on the skip to engage the primary engagement mechanism; and displacing the primary engagement mechanism in order to displace the opening means so as to open the door of the skip.

The method may also include the step of displacing the skip past the secondary engagement mechanism in order for opening means on the chute to engage the secondary engagement mechanism so as to displace the chute.

BRIEF DESCRIPTION OF THE DRAWINGS

A preferred embodiment of the invention is described by way of a non-limiting example, and with reference to the accompanying drawings in which:

Figure 1 is a side view of a skip used with the door opening arrangement of the invention;

Figure 2 is a front view of the skip of figure 1 ;

Figure 3 is a side view of the skip of figure 1 positioned inside a discharge station that includes the door opening arrangement of the invention; Figure 4 is a front view of the skip of figure 3;

Figure 5 shows the skip of figure 1 with the chute having been displaced; and

Figures 6 to 8 show the door of the skip progressively being opened by way of the door opening arrangement.

DETAIL DESCRIPTION OF THE INVENTION

Referring to the drawings a non-limiting example of a door opening arrangement in accordance with the invention is generally indicated by reference numeral 10.

A skip, as is shown in figures 1 and 2, for conveying ore in a mining operation is indicated by reference numeral 20, and comprises a hollow body 21 having operatively upper 21.1 and operatively lower 21.2 ends. The hollow body 21 of the skip 20 is elongate, and is substantially rectangular when viewed in cross section. A charge opening 22 is located towards the upper end 21.1 of the skip 20, and is used for charging the skip 20 with ore to be conveyed. The lower end 21.2 of the skip terminates in a sloping bottom section that leads to a discharge opening 23 through which ore is discharged under gravity once conveyed to a required location. The skip 20 is carried by a bridle type frame configuration comprising an upper crossbar or transom 24 and a lower crossbar or transom 26, the transoms being interconnected by longitudinal stringers 25. The discharge opening 23 is cioseable by way of a displaceable door 40, which is pivotably secured to either the stringers 25 or the body 21 of the skip 20 by way of a pivot arrangement 41. Opening means 42, in this embodiment in the form of rollers extending from sides of the door 40, are provided, and are used to displace the door 40 between closed (figure 3) and open (figure 8) positions as is described in more detail hereinbelow. The pivot arrangement 41 of the door 40 is offset relative to a center of gravity of the door to ensure that the door is gravitationally biased towards the closed position.

A chute 50 is also pivotably secured to the skip 20 by way of a pivot arrangement 51 , and is located below the door 40. The chute 50 is displaceable between a retracted position (shown in figure 3) and an extended position (shown in figure 5). An edge 54 of the chute extends beyond the body 21 of the skip 20 when the chute is in the extended position, and aids in discharging ore into the discharge vessel 27 with minimum spillage. The chute 50 also includes opening means 52, in this embodiment in the form of rollers extending form sides of the chute 50, which are used to displace the chute between the retracted and extended positions as is described in more detail hereinbelow. The pivot arrangement 51 of the chute 50 is offset relative to a center of gravity of the chute to ensure that the chute is gravitationally biased towards the retracted position.

The door 40 and chute 50 have complementary locking formations that prevent the door from being opened prior to the chute 50 having been displaced to the extended position. The chute 50 therefore also acts as a lock for the door 40 when the chute is in the retracted position, to which position the chute is biased under gravity. In this particular embodiment the locking formations comprise a locking pin 43 extending from the door 40, and a complementary locking latch 53 extending from the chute 50. In use the skip 20 is loaded with ore through the charge opening 22 at a first location, typically on the level in the mine where the ore is mined. Once full, the skip 20 is transported to a discharging station, typically in the headgear (not shown), where the ore is discharged into a discharge vessel 27 via the discharge opening 23. An actuating assembly 30 is provided at the discharge station to automatically open the door 40 and chute 50 of the skip 20 when a predetermined position is reached when the skip 2 is upwardly displaced into the discharge station.

The actuating assembly 30, as is best seen in figure 3, comprises an actuator 31 in the form of a piston and cylinder arrangement, and a primary engagement mechanism 32 pivotably connected to the actuator 31. An end of a piston 31.2 of the actuator 31 is pivotably connected to the primary engagement mechanism 32, and a cylinder 31.1 of the actuator 31 is pivotably connected to a stationary surface in the headgear by way of a pivot arrangement 31.3. The primary engagement mechanism 32 is also pivotably connected to a stationary surface in the headgear by way of a pivot arrangement 32.3.

The primary engagement mechanism 32 is in the form of a base 32.1 from which elongate strips extend so as to form a track 32.2, commonly referred to as a tipping path, suitable for receiving the opening means 42 in the form of rollers that extend from the door 40. It will be appreciated that the primary engagement mechanism may be of many different configurations, and that the track 32.2 may also be formed in many different ways, such as providing a length of channel shaped steel that is pivotably connected to a stationary surface at the headgear. The track 32.2 is arcuate when viewed in plan, and the concave side of the track is directed towards the skip, whereas the convex side is directed away from the skip. The door opening arrangement 10 also includes a secondary engagement mechanism 60 in the form of a stationary track 61.1 , commonly referred to as a stationary tipping path, mounted on a stationary surface at the headgear. When viewed in plan, the track 61.1 includes a displacement zone causing the ends of the track 61.1 to be axially spaced apart but parallel, the purpose of which will become apparent hereinbelow. The track 61.1 is adapted to receive the opening means 52 in the form of rollers extending from the chute 50.

Primary engagement formations 32 and secondary engagement formations 60 are provided on both sides of the skip 20, so as to engage opening means 42, 52 extending from both sides of the door 40 and chute 50.

When the skip 20 has been filled with ore, it is transported to a discharge station in order to discharge the ore into a suitable discharge vessel 27. The skip 20, as it arrives at the discharge station, is shown in figures 3 and 4. At this initial stage the rollers 52 extending from the chute 50 have already entered the track 60.1 of the secondary engagement mechanism 60, but the chute 50 has not been displaced yet. The rollers 42 extending from the door 40 has also entered the track 32.2 of the primary engagement mechanism 32, but the movement of the rollers 52 is still linear, and the door 40 has also not been displaced. At this time the locking latch 53 extending from the chute 50 is still engaging the locking pin 43 extending from the door, thus preventing any displacement of the door 50.

Upon continued upward displacement of the skip 20, as is seen in figure 5, the rollers 52 extending from the chute 50 are displaced through the displacement zone 60.2 in the track 60.1 , thus causing the rollers 52 to be outwardly displaced, and resulting in the chute 50 pivoting about the pivot arrangement 51 so as to displace the chute 50 from the retracted position (figure 3) to the extended position (figure 5). The chute 50 tilts sufficiently for its bottom edge 54 to overhang the discharge vessel 27 in the headgear, thereby preventing broken rock and ore from spilling between the chute 50 and the discharge vessel 27 while the content of the skip 20 is being discharged. At the same time, the locking latch 53 on the chute 50 disengages the locking pin 43 on the door 40, thus allowing the door to be displaceable. When this position has been reached, the rollers 42 extending from the door 40 have also sufficiently entered the track 32.2 of the primary engagement mechanism 32 to allow the door opening sequence to commence.

The door 40 is opened by actuating the actuator 31 , thus causing the primary engagement mechanism 32, and in particular the track 32.2 in which the roller 42 is located, to be displaced away form the skip 20. This causes the door 40 to be pulled open, thus resulting in the ore being discharged through the discharge opening 23. The door opening sequence is shown in figures 5 to 8. A constant displacement of the track 32.2, and thus opening rate of the door 40, is ensured by providing an arcuate track 32.2 that compensates for the accentuated displacement of the primary engagement mechanism as the roller moves away from the pivot point 32.2.

When the skip 20 has been discharged the sequence is reversed by extending the actuator to its original position, and by lowering the skip so that the rollers 52 of the chute 50 exits the track 60.1 so as to be displaced to the original position under gravity. The locking latch 53 on the chute 50 again engages the locking pin 43 on the door 40 so as to lock the door 40 to prevent displacement thereof. It is an important aspect of this invention that the door 40 of the skip is opened without the need for excessive upward displacement of the skip 20, as would for instance have been the case if a stationary tipping track or tipping path (similar to the second engagement mechanism, but substantially longer) was used. When a stationary tipping path is used, the discharging skip must first be discharged before it stops in an upper position. The bottom skip that is awaiting loading is still moving down whilst the discharging skip is being discharged, and the bottom skip only comes to rest in a loading position once the upper skip has been discharged. The loading of the bottom skip and the discharging of the upper skip can therefore not be done simultaneously, thus resulting in a total system delay. The loading and discharging steps each takes about 15 seconds, whereas the entire cycle is in the order of 120 seconds for a shaft being 1000m deep. This invention, that allows loading and discharging to happen simultaneously, therefore results in a time saving of 15 seconds, and in a total capacity increase of about 12.5%.

It will be appreciated that the above is only one embodiment of the invention, and that there may be many variations without departing from the spirit and/or scope of the invention. For example, the skip and door opening arrangement in accordance with the invention need not include a chute, and the chute also need not be closed by way of a stationary tipping path. It is also foreseen that the track and the opening means of the primary engagement mechanism and the door respectively, may be inverted in that the track may be located in or on the door, whereas the opening means, in the form of a roller, may form part of the first engagement mechanism. Still further, it will be appreciated that configurations other than a pivotable track may be utilized, provided that there is some form of displacement of the primary engagement mechanism away from the skip.

Claims

CLAIMS:

1. A door opening arrangement, suitable for use in opening a door of a skip positioned in a discharge station, the door opening arrangement including: an actuating assembly provided at the discharge station; the actuating assembly having a primary engagement mechanism being adapted releasably to engage an opening means connected to the door of the skip; the primary engagement mechanism being displaceable between a first position wherein the engagement mechanism is located adjacent the skip, and a second position wherein at least part of the primary engagement mechanism is displaced so as to displace the opening means, in so doing opening the door of the skip.

2. The door opening arrangement according to claim 1 wherein the primary engagement mechanism is adapted to open the door of the skip while the skip remains substantially stationary.

3. The door opening arrangement according to claim 1 or claim 2 wherein the primary engagement mechanism includes a track that is adapted to receive the opening means.

4. The door opening arrangement according to claim 3 wherein the primary engagement mechanism is pivotably mounted, in order for the track to be pivotable between the first and the second positions.

5. The door opening arrangement according to claim 3 wherein the primary engagement mechanism is slideably mounted, in order for the track to be slideable between the first and the second positions.

6. The door opening arrangement according to any one of claims 3 to 5 wherein the track is elongate.

7. The door opening arrangement according to any one of claims 3 to 6 wherein the track is of arcuate configuration.

8. The door opening arrangement according to claim 7 wherein a concave side of the arcuate track is directed towards the door of the skip.

9. The door opening arrangement according to any one of claims 3 to 8 wherein the track is in the form of two substantially parallel elongate strips extending from a base plate.

10. The door opening arrangement according to any one of the preceding claims wherein the actuating assembly includes an actuator.

11. The door opening arrangement according to claim 10 wherein the actuator is hydraulically, pneumatically or electrically actuated.

12. The door opening arrangement according to claim 11 wherein the actuator is in the form of a piston and cylinder assembly.

13. The door opening arrangement according to any one of claims 10 to 12 wherein the actuator is pivotably mounted at the discharge station, and is pivotably connected to the primary engagement mechanism.

14. The door opening arrangement according to any one of the preceding claims wherein the opening means is in the form of at least one extension that extends from the door.

15. The door opening arrangement according to any one of claims 1 to 14 wherein the opening means extends from a linking arm that is connected to the door.

16. The door opening arrangement according to claim 14 or claim 15 wherein the opening means terminates in a rotatable member in the form of a roller.

17. The door opening arrangement according to claim 16 wherein the primary engagement mechanism defines a cam surface upon which the opening means can be displaced, the roller of the opening means acting as a cam follower.

18. The door opening arrangement according to claim 1 or 2 wherein the opening means is in the form of a track located in the door, and the primary engagement means includes a roller for engaging the track in the door.

19. The door opening arrangement according to any one of the preceding claims including a secondary engagement mechanism suitable for engaging an opening means located on a chute that is pivotably secured to the skip.

20. The door opening arrangement according to claim 19 wherein the secondary engagement mechanism is in the form of a track.

21. The door opening arrangement according to claim 20 wherein the the track is stationary.

22. The door opening arrangement according to any one of claims 19 to 21 wherein the secondary engagement mechanism is located below the primary engagement mechanism, in order for the opening means located on the chute to engage the secondary engagement mechanism prior to the opening means connected to the door engaging the primary engagement mechanism.

23. An actuating assembly, suitable for opening a door of a skip, the actuating assembly including: an actuator that is displaceable between first and second positions when actuated, and an elongate track connected to the actuator; the elongate track being displaceable by the actuator when the actuator is actuated

24. The actuating assembly of claim 23 wherein the elongate track is pivotably mounted to a stationary surface at a discharge station, so as to be pivotably displaceable by the actuator when actuated.

25. A method for opening a door of a skip including the steps of: providing a door opening arrangement as claimed in any one of claims 1 to 22; displacing the skip relative to the primary engagement mechanism in order for the opening means on the skip to engage the primary engagement mechanism; and displacing the primary engagement mechanism in order to displace the opening means so as to open the door of the skip.

26. The method of claim 25 including the step of displacing the skip past the secondary engagement mechanism in order for opening means on the chute to engage the secondary engagement mechanism so as to displace the chute.