Controlled electromagnetic induction detonation system for initiation of a detonatable material

• US 6,422,145 B1
• Filed: 07/10/2000
• Issued: 07/23/2002
• Est. Priority Date: 11/06/1997
• Status: Expired due to Fees

• Current Assignee: Rocktek USA, Ltd.
• Original Assignee: Rocktek USA, Ltd.
• Inventors: Wright, Keith, Gavrilovic, Mihailo
• Primary Examiner(s): Carone, Michael J.
• Assistant Examiner(s): Semunegus, Lulit
• Application Number:
  US09/530,816
• Time in Patent Office: 743 Days
• Field of Search: 102/202.1, 102/202.2, 102/200, 102/206, 102/221, 102/301
• US Class Current: 102/200
• CPC Class Codes: F42C 13/047 Remotely actuated projectile fuzes operated by radio transmission links
• CPC Class Codes: F42D 1/05 Electric circuits for blasting

Abstract

The controlled electromagnetic induction detonation system for initiation of a detonatable material system includes an automated radio charge (ARCH) module connectable to an electric detonator, a transducer module for providing operational power by electromagnetic induction to the ARCH module, and a remote controller for sending instructions to the transducer module from a location remote from the detonator. Upon completion of an arming sequence, the transducer module generates an electromagnetic field which is picked up by a coil in the ARCH module and used to power the ARCH module and provide a detonation current for the detonator. The transducer module or at least a coil thereof which produces the electromagnetic field is supported on or in a stemming bar which in turn acts as a core of an electromagnet confining the magnetic flux for pick up by the ARCH module. Multilevel access control and interlock systems operate between the remote controller, transducer unit and the ARCH module to reduce the likelihood of unintentional initiation of the detonator.

Claims

1. A controlled electromagnetic induction detonation system for decoupled in hole initiation of an energetic substance, said system including:

an automated radio charge (ARCH) module coupled to an energetic substance and deposited in a hole formed in a hard material, the ARCH module having no permanent onboard power source but including a power circuit for extracting by means of electromagnetic induction operational power from a remotely generated electromagnetic field, the power circuit providing operational power for-the-ARCH module and arranged to generate a detonation current deliverable to the energetic substance, and means for receiving and decoding radio transmitted control signals including a FIRE code, the verified receipt of which causes delivery of the detonation current to the energetic substance;

a stemming bar for stemming the hole in which the energetic substance and ARCH module are deposited; and

,

a transducer unit for radio transmitting said control signals, said transducer unit having a coil for generating the electromagnetic field, the coil mounted on or in the stemming bar to effect the transfer of operational power to the ARCH module by electromagnetic induction.

2. A system according to claim 1 wherein the means for receiving and decoding the control signal extracts the control signal from said electromagnetic field.

3. A system, according to claim 2, wherein said ARCH module further includes an output switch through which said detonation current most flow, in order to initiate the energetic substance, said switch maintained as a short circuit until receipt and verification of said FIRE code, in which instance, said switch is operated to remove said short circuit and allow the detonation current to flow to the energetic substance.

4. A system, according to claim 3, wherein said transducer unit includes:

a power supply for supplying power to electromagnetic field generating means for generating said electromagnetic field; and

,

radio transceiver means for radio transmitting said control signals to the ARCH module.

5. A system according to claim 4 wherein said transducer unit further includes means for impressing said control signals onto said electromagnetic field so that said radio transceiver means transmits both said electromagnetic field and said control signals to said ARCH module.

6. A system according to claim 4 wherein said transducer unit includes a mode switch switchable between a LOCAL mode and a REMOTE mode of operation, wherein in said LOCAL mode of operation, a user can manually input instructions to said transducer unit for radio transmission to said ARCH module and wherein in said REMOTE mode of operation, a user can input instructions to said transducer unit via a remote controller unit.

7. A system according to claim 6 wherein said transducer unit includes means for manual entry of instructions and a timer means both operationally associated with said mode switch whereby on switching said mode switch to the LOCAL mode, a user must enter via said entry means a valid identification number recognised by said transducer unit within a predetermined period of time timed by said timer means in order for further user instructions to be acted upon by said transducer unit, and in the absence of the entry of a valid identification number within said time period said transducer unit automatically shuts down so as to be non responsive to user input instructions for a second period of time timed by said timer means.

8. A system according to claim 7 wherein said transducer unit includes an ARM switch functional when said transducer unit is in the LOCAL mode of operation which, when activated causes said electric field generating means to generate said electromagnetic field.

9. A system according to claim 8 wherein said transducer unit includes a FIRE switch functional when said transducer unit is in the LOCAL mode of operation and which when activated within a predetermined time period after activation of the ARM switch causes the transducer unit to transmit the FIRE code to the ARCH module.

10. A system according to claim 6 further including a remote controller unit by which a user can communicate instructions to said transducer unit from a location remote from said transducer unit.

11. A system according to claim 10 wherein said remote controller unit includes means for the manual entry of instructions by which a user must enter a valid identification number within a predetermined time period in order for said remote controller to establish a radio communication link with said transducer unit.

12. A system according to claim 11 wherein said remote controller unit includes processor means for generating a unique identification code word which is continuously transmitted until an acknowledgment signal is received from said transducer unit corresponding to said identification code word, and wherein in the absence of receipt of said acknowledge signal within a predetermined time period said remote controller unit enters a RESET mode in which a user must once again enter a valid identification number to reinitiate the establishment of the radio communication link with said transducer unit.

13. A system according to claim 12 wherein said remote controller unit further includes an ARM switch which upon activation, when a radio communication link has been established with said transducer unit, causes the remote controller unit to transmit an ARM code to transducer unit upon which said transducer unit generates said electromagnetic field.

14. A system, according to claim 13, wherein said transducer unit sends said acknowledgment signal t6 said remote controller unit upon receipt of the ARM code and said transducer unit thereafter initiates its timer means to time a first period within which to receive a FIRE code from said remote controller unit, wherein the absence of receipt of said FIRE code within said first period said transducer unit automatically shuts down for a second period of time.

15. A system, according to claim 14, wherein said remote control unit includes a FIRE switch, which, when activated causes the remote control unit to transmit a FIRE code to said transducer unit which in turn upon on verified receipt thereof transmits said FIRE code to said ARCH module.

16. A system according to claim 15 wherein the FIRE code transmitted by the remote controller to transducer unit is different to the FIRE code retransmitted by the transducer unit to the ARCH module.

17. A controlled electromagnetic induction detonation system for initiating an energetic substance, the system including:

an automated radio charge (ARCH) module for delivering an electric detonation current to an energetic substance, said ARCH module having no permanent power source but including a power circuit for extracting power by means of electromagnetic induction from a electromagnetic field generated remotely from the ARCH module, the power circuit providing operational power for the ARCH module and the electric detonation current, and means for receiving and decoding radio transmitted control signals including a FIRE code, the verified receipt of which causes the ARCH module to deliver said current to and thereby initiate the energetic substance.

18. A system, according to claim 17, wherein the means for receiving and decoding the control signal extracts the control signal from said electromagnetic field.

19. A system, according to claim 18, wherein said ARCH module further includes an output switch through which said detonation current must flow, in order to initiate the energetic substance, said switch maintained as a short circuit until receipt and verification of said FIRE code, in which instance, said switch is operated to remove said short circuit and allow the detonation current to flow to the energetic substance.

20. A system, according to claim 19, wherein said transducer unit includes:

a power supply for supplying power to electromagnetic field generating means for generating said electromagnetic field; and

,

radio transceiver means for radio transmitting said control signals to the ARCH module.

21. A system, according to claim 20, wherein said transducer unit further includes means for impressing said control signals onto said electromagnetic field so that said radio transceiver means transmits both said electromagnetic field and said control signals to said ARCH module.

22. A system, according to claim 21 further including a stemming bar for stemming a hole in which said ARCH module and detonator can be deposited and wherein said transducer unit includes a coil for generating said electromagnetic field, said coil mounted on or in the stemming bar so that lines of magnetic flux pass through the stemming bar and link with the power circuit to transfer operational power to the ARCH module by electromagnetic induction.

23. A system, according to claim 22, wherein said transducer unit includes a mode switch switchable between a LOCAL mode and a REMOTE mode of operation, wherein in said LOCAL mode of operation, a user can manually input instructions to said transducer unit for radio transmission to said ARCH module and wherein in said REMOTE mode of operation, a user can input instructions to said transducer unit via a remote controller unit.

24. A system, according to claim 23, wherein said transducer unit includes means for manual entry of instructions and a timer means both operationally associated with said mode switch whereby on switching said mode switch to the LOCAL mode, a user must enter via said entry means a valid identification number recognized by said transducer unit within a predetermined period of time timed by said timer means in order for further user instructions to be acted upon by said transducer unit, and in the absence of the entry of a valid identification number within said time period said transducer unit automatically shuts down so as to be non responsive to user input instructions for a second period of time timed by said timer means.

25. A system, according to claim 24, wherein said transducer unit includes an ARM switch functional when said transducer unit is in the LOCAL mode of operation which, when activated causes said electric field generating means to generate said electromagnetic field.

26. A system, according to claim 25, wherein said transducer unit includes a FIRE switch functional when, said transducer unit is in the LOCAL mode of operation and which when activated within a predetermined time period after activation of the ARM switch causes the transducer unit to transmit the FIRE code to the ARCH module.

27. A system, according to claim 26, further including a remote controller unit by which a user can communicate instructions to said transducer unit from a location remote from said transducer unit.

28. A system, according to claim 27, wherein said remote controller unit includes means for the manual entry of instructions by which a user must enter a valid identification number within a predetermined time period in order for said remote controller to establish a radio communication link with said transducer unit.

29. A system, according to claim 28, wherein said remote controller unit includes processor means for generating a unique identification code word which is continuously transmitted until an acknowledgment signal is received from said transducer unit corresponding to said identification code word, and wherein in the absence of receipt of said acknowledge signal within a predetermined time period said remote controller unit enters a RESET mode in which a user must once again enter a valid identification number to reinitiate the establishment of the radio communication link with said transducer unit.

30. A system, according to claim 29, wherein said remote controller unit further includes an ARM switch which upon activation, when a radio communication link has been established with said transducer unit, causes the remote controller unit to transmit an ARM code to transducer unit upon which said transducer unit generates said electromagnetic field.

31. A system, according to claim 30, wherein said transducer unit sends said acknowledgment signal to said remote controller unit upon receipt of the ARM code and said transducer unit thereafter initiates its timer means to time a first period within which to receive a FIRE code from said remote controller unit, wherein the absence of receipt of said FIRE code within said first period said transducer unit automatically shuts down for a second period of time.

32. A system, according to claim 31, wherein said remote control unit includes a FIRE switch, which, when activated causes the remote control unit to transmit a FIRE code to said transducer unit which in turn upon on verified receipt thereof transmits said FIRE code to said ARCH module.

33. A system, according to claim 32, wherein the FIRE code transmitted by the remote controller to transducer unit is different to the FIRE code retransmitted by the transducer unit to the ARCH module.

34. A method of decoupled in-hole initiation of an energetic substance including the steps of:

depositing an energetic substance in a hole formed in a hard material;

coupling an electronic circuit to said energetic substance;

mounting a coil on or in a stemming bar;

stemming said hole with said stemming bar;

energizing the coil to produce an electromagnetic field;

extracting from said electromagnetic field, by said electronic circuit, operational power to generate a detonation current; and

,

delivering said detonation current to said energetic substance to initiate said energetic substance.

35. The method according to claim 34 further including the steps of radio transmitting a control signal which includes a FIRE code;

receiving said FIRE code;

decoding said FIRE code;

verifying said FIRE code; and

,

wherein said delivering step is effected only after a verified receipt of said FIRE code and wherein the electronic circuit performs the steps of receiving, decoding and verifying.

36. The method according to claim 35 wherein said transmitting step includes impressing said control signal onto said electromagnetic field.

37. The method according to claim 36 further including the step of providing an output switch through which said detonation current must flow in order to initiate said energetic substance and maintaining said output switch in a short circuit condition until receipt and verification of said FIRE code;

and,

upon receipt and verification of said FIRE code, removing said short circuit to enable said detonation current to flow to said energetic substance.