# US 11,441,883 B2 · Bidirectional wireless detonator system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,441,883 B2 - Document ID: US11441883B2 - Status: Granted - Kind: B2 - Application number: 17/268,035 - Filed: 2019-08-15 - Published: 2021-10-14 - Granted: 2022-09-13 - Earliest claimed: 2018-08-16 - Assignees: Detnet South Africa (Pty) Ltd - Applicants: Detnet South Africa (Pty) Ltd - Inventors: Daniel August Julien Louis Maurissens; Elmar Lennox Muller - Web page: https://patentgrep.com/patent/US11441883B2 ## CPC - F42D 1/02: Arranging blasting cartridges to form an assembly (adaptation of blasting cartridges therefor F42B3/02) - F42D 1/055: specially adapted for firing multiple charges with a time delay - F42D 3/04: for rock blasting - H04W 4/80: Services using short range communication, e.g. near-field communication [NFC], radio-frequency identification [RFID] or low energy communication - F42D: BLASTING (fuses, e.g. fuse cords, C06C5/00; {for obtaining fluid from wells E21B43/00; for mining or quarrying E21C37/00; for making tunnels or galleries E21D9/006}; cartridges F42B3/00) - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) ## Abstract A blasting system which includes control equipment and a plurality of detonators which are located in respective boreholes formed in rock, wherein signals from the detonators are magnetically transmitted wirelessly through the rock to the control equipment via different paths between successive detonators, and wherein a signal from the control equipment can be simultaneously transmitted to all of the detonators. ## Claims ### Claim 1 A blasting system which includes a control antenna, control equipment and a plurality of detonators, wherein each detonator is located in a respective borehole formed in rock and includes a respective transmitter and receiver and is adapted to magnetically communicate wirelessly through the rock in a two-directional manner with a number of detonators, fewer than all of the plurality of detonators, which number of detonators are disposed in adjacent boreholes, whereby a signal from the control equipment is transmitted by the control antenna through the rock and is then relayed in succession via the respective transmitters and receivers of at least some of the plurality of detonators along a plurality of outbound paths in the rock to all the plurality of detonators, and a signal from any detonator is relayed in succession via the respective transmitters and receivers of at least some of the plurality of detonators along a respective inbound path in the rock to the control antenna, and wherein the control equipment is operable to transmit a signal from the control antenna through the rock simultaneously to all of the detonators. ### Claim 2 (depends on 1) A blasting system according to claim 1 wherein one of said plurality of detonators is a sink detonator which is in direct communication with the control equipment. ### Claim 3 (depends on 2) A blasting system according to claim 2 wherein each detonator is configured to communicate wirelessly through the rock with a number of adjacent detonators, fewer than all of the plurality of detonators, whereby a signal from any detonator is relayed via successive detonators to the sink detonator, which transmits the signal to the control antenna. ### Claim 4 (depends on 2) A blasting system according to claim 2 wherein the control equipment is connected to the sink detonator by means of a physical link. ### Claim 5 (depends on 2) A blasting system according to claim 2 wherein the control equipment is in signal communication with the sink detonator via the control antenna. ### Claim 6 (depends on 1) A blasting system according to claim 1 wherein each of said signals is at a frequency of 4 kHz, and is modulated to carry information. ### Claim 7 (depends on 1) A blasting system according to claim 1 wherein each of said plurality of detonators includes a respective unique identifier. ### Claim 8 (depends on 7) A blasting system according to claim 7 wherein each said outbound path is determined by a sequence of said unique identifiers respectively associated with the respective plurality of detonators along said outbound path. ### Claim 9 (depends on 7) A blasting system according to claim 7 wherein each said inbound path is determined by a sequence of said unique identifiers respectively associated with the respective plurality of detonators along said inbound path. ### Claim 10 (depends on 1) A blasting system according to claim 1 wherein said signal which is transmitted by the control equipment simultaneously to all the detonators is selected from a signal to synchronize the operation of the detonators; a signal to arm the detonators; and a signal to fire the detonators. ### Claim 11 (depends on 1) A blasting system according to claim 1 wherein each of said plurality of detonators includes a respective said transmitter which, when actuated, transmits a first signal at a known, predetermined signal strength, a respective said receiver which, in operation, receives said first signal from another detonator which is the same as said detonator and which is displaced by a distance from said detonator, a comparator which compares the strength of the transmitted first signal to the strength of said received first signal, and a processor, responsive to the comparator, operable to provide a measurement of the difference between the strength of the transmitted first signal and the received first signal.