AU2002100859A4 - Electronic detonator buffered connection device - Google Patents

Description

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION INNOVATION PATENT ELECTRONIC DETONATOR BUFFERED CONNECTION DEVICE The following statement is a full description of this invention, including an example of its application.

This invention relates to an improved electronic detonator system that is capable of reliable operation under adverse conditions where damage to wiring systems and communications networks is likely.

Conventional blasting for the purpose of breaking rock commonly uses a plurality of detonators placed into holes drilled into rock (blast-holes) for the purpose of initiating explosives charges in a set firing interval.

Conventional delay detonators incorporate a burning fuse time element that provides a 'delay'. This 'delay' is a period of time from the instant the initiating signal reaches the detonator to the instant that the detonator explodes.

Recent developments in the art relate to 'electronic delay detonator systems' whereby each detonator has some form of internal programmable memory, timing device and processor that allows it to be programmed with a 'delay'. Persons skilled in the art will recognise that this 'delay' refers to the time difference between receiving an electronic "FIRE" command and the detonator exploding.

Using FIG. 1 as a reference, it can be diagrammatically explained that current electronic delay detonator systems incorporate a plurality of detonators 14, 14a, 14b. Each detonator must be connected by in-hole connection lines 16, 16a, 16b to a 'Surface Command and Control Network' line 12, and hence to a centralised 'Command and Control Unit' 11 that provides communication and control to each detonator connected to it.

The Surface Command and Control Network 12 is the wiring or other communication medium that links the Command and Control Unit to the detonator connections at the top of each blast-hole 19.

In order to program the detonator memory with a 'delay' and to subsequently transmit the required electrical signals and power that enable each detonator to explode, a means of communication between each detonator and the Surface Command and Control Network 12 is required. This is provided by the in-hole connection lines 16 between the detonator 14 and the Surface Command and Control Network 12.

Persons skilled in the art use the term 'down-line' to refer to the in-hole connection lines 16 between the detonator 14 and the initial connection outside the blast-hole 19. In FIG. 1 these are identified as 16, 16a and 16b. In current electronic detonator embodiments these downlines may take the form of conductive wires, or a linear explosive device.

The physical act of placing a detonator inside a blast-hole 15 drilled into the rock mass to be blasted and the subsequent loading of explosive 18 and non-explosive 17 material into said blast-hole may cause damage to the said 'down-line' 16 in regions that are inaccessible, 13, 13a, 13b. Damage may also be caused after loading due to movement of the rock mass or by movement of the explosive and non-explosive material within the blast-hole. Damage caused to down-lines within a blast-hole can not generally be repaired, as there is not access to the damaged portion.

The damage caused to detonator down-lines utilising a number of conducting wires as a communication medium is apt to cause electrical problems including current leakage, short circuits or open circuits. Current electronic delay detonator systems have the disadvantage that should a down-line become damaged communication and control may be lost, not only to that specific detonator, but to other detonators connected to the specific Surface Command and Control Network 12. For example a short circuit at location 13b would case loss of electrical communication from the Command and Control Unit 11 to detonators 14, 14a and 14b.

Furthermore where damage to more than one detonator down-line has occurred it may be very difficult for an operator to determine and rectify the fault since the faults may be electrically superimposed. In current embodiments the identification of multiple electrical down-line faults generally requires the system to be broken down into a number of parts and a check of the individual parts of the system to be performed until such faults can be individually isolated, identified and removed.

A second disadvantage of these current systems is that the Surface Command and Control Network 12 is directly connected to a plurality of down-lines for each of the plurality of detonators comprising the blasting system. Thus damage to any of the detonator down-lines, particularly a short circuit, can effect the ability of the Surface Command and Control Network 12 to function electrically. In a large rock blasting application there may be many hundreds of down-lines directly connected to a single Surface Command and Control Network. Damage to one or more of the down-lines can cause system failure.

These problems are overcome by the present invention that provides an 'Electronic Detonator Buffered Connection Device' for each blast-hole. An Electronic Detonator Buffered Connection Device is a device that provides electrical isolation from the surface command and control network and the electronic detonators. The 'Electronic Detonator Buffered Connection Device allows bidirectionial communication between the Command and Control Unit and the electronic detonators while maintaining electronic isolation. The terms used here will be understood by a person skilled in the art of electronic design.

An Electronic Detonator Buffered Connection Device comprises connection devices for connection to the detonator down-lines and to the Surface Command and Control Network.

The Electronic Detonator Buffered Connection Device connects to the Surface Command and Control Network and provides a bi-directional connection between connected Electronic Detonators and the Surface Command and Control Network. The power for the Electronic Detonator Buffered Connection Device is extracted from the Surface Command and Control Network and converted to provide voltages to drive the receive and transmit buffers. The Surface Command and Control Network is also connected to the buffers so that the Command and Control Unit signals can be received and the Electronic Detonator signals can be retransmitted. The Electronic Detonator Buffered Connection Device is also connected to the Electronic Detonator and the buffers use this connection to transmit to and receive signals from the Electronic Detonator.

The Electronic Detonator Buffered Connection Device may also incorporate signal processing and signal generating hardware and software. The Electronic Detonator Buffered Connection may also incorporate electronic memory and may incorporate a time measuring device that is driven by an internal oscillator or by external signal generated by the Command and Control Unit.

A benefit of the invention is that every detonator is electronically isolated from the Surface Command and Control Network. Thus any electronic disruptions that may occur between the Electronic Detonator Buffered Connection Device and any connected electronic detonators will not effect the Surface Command and Control Network nor any other Electronic Detonator Buffered Connection Devices up or down the line. Some common disruptions that occur are short circuits, current leakage, voltage fluctuations, voltage spikes, resistance variations and RF interference all of which can effect communications and some of which could, without the Electronic Detonator Buffered Connection Device, stop the Surface Command and Control Network communicating with other electronic detonators. The buffer achieves this by isolating the two parts of the system while still providing bi-directional communication This invention ensures that the Surface Command and Control Network is not compromised by the failure of any one or more detonator down-lines since the Surface Command and Control Network is isolated from the detonator down-lines by the Electronic Detonator Buffered Connection Device.

This invention will ensure that signals transmitted from the Command and Control Unit will be received uninterrupted at each down-line connection independent of any damage to or any interference generated by any one or more down-lines connected to the surface command and control network via an Electronic Detonator Buffered Connection Device.

In the preferred embodiment each detonator is provided with an integral Electronic Detonator Buffered Connection Device for connecting the down-line to the surface command and control network.

The invention will now be described further by way of example with reference to the accompanying drawings in which, FIG. 2 shows, diagrammatically, the detonator, the down-line and the Electronic Detonator Buffered Connection arrangement.

FIG. 3 shows, diagrammatically, the Electronic Detonator Buffered Connection Device Block Diagram.

In the preferred embodiment illustrated in FIG. 2 an Electronic Detonator Buffered Connection 20 is connected to a detonator down-line 16 which is also connected to an electronic detonator.

In the preferred embodiment these are factory-made connections.

In another embodiment as described in FIG 2a a single Electronic Detonator Buffered Connection is connected to a plurality of detonator down-lines. In this case the Electronic Detonator Buffered Connection Device has a plurality of independent output connections such that individual detonator down-lines may be connected without potential for crossed communications. The Electronic Detonator Buffered Connection Device provides a connector to which mulitple Electronic detonators can be attached on site. Each connection will be independent of the other and the the Electronic Detonator Buffered Connection Device will provide separate buffering and communication for each one.

To explain diagrammatically with reference to FIG 3 an example of the use of the above arrangement in practise, in a conventional rock blasting application, each detonator of a plurality is loaded into a blast-hole according to a pre-arranged design. The detonators are connected to the surface command and control network via a down-line and an integral Electronic Detonator Buffered Connection Device located on the surface adjacent to the surface command and control network.

Communication signals coming from the command and control unit are received by the Electronic Detonator Buffered Connection Device at the SCCN connector 21 in Fig 3. The Power Supply 32 converts the signals received to provide voltages to power the SCCN Input and Output Buffers 30 and 31. The SCCN Input Buffer 30 receives the incoming signals and retransmits them to an Electronic Detonator and provides electronic isolation between the input and output stages of the buffer. The SCCN Output Buffer 31 receives the incoming signals from the Electronic Detonator and retransmits them to the SCCN and provides electronic isolation between the input and output stages of the buffer. There are a number of methods of providing the isolation and the re-transmission well understood by a person skilled in the art of electronic design.

Communication integrity can therefore be maintained by the Electronic Detonator Buffered Connection Device even when there are multiple failures of the detonator downlines Whilst the present invention has been described by way of example the invention is not restricted thereto and many modifications and variations will be apparent to persons skilled in the art.

PETER JAMES DUNIAM Sunday 3 November 2002 ROBIN Marka~s SANDS Sunday 3 November 2002

Claims (5)

1. A device, known as an Electronic Detonator Buffered Connection Device, that provides a connection between an electronic detonator down-line and a Surface Command and Control Network such that independent signalling is provided to and from each electronic detonator connected to it and to and from the command and control unit.

2. The Electronic Detonator Buffered Connection Device of claim 1 that is capable of receiving signals from the command and control unit and retransmitting these signals at one or more independent outputs where electronic detonators have been connected thus isolating each individual detonator amongst a plurality of detonators connected to the surface command and control network through the Electronic Detonator Buffered Connection Device of claim 1

3. The Electronic Detonator Buffered Connection Device of claims 1 and 2 wherein the Electronic Detonator Buffered Connection Device incorporates a plurality of independent connections enabling it to be connected to a plurality of electronic detonators.

4. The connection device of previous claims wherein the connection device has an integrated processor and memory and is enabled to perform analysis and calculation in order to modify or generate new signals or commands based on predetermined rules contained in the embedded software.

5. The Electronic Detonator Buffered Connection Device of previous claims that, in addition to connections to a surface command and control network and to a plurality of electronic detonator downlines, has connection devices that enable it to communicate with external devices including, but not limited to, personal computers, specialised PIC programming devices via hardwired or remote connection using infrared, radio frequencies, sound, light or any of the many other currently known methods of transporting information between two systems. PETER JAMES DUNIAM Sunday 3 November 2002 ROBIN Mark SANDS Sunday 3 November 2002