Detonator actuator

• US 5,090,321 A
• Filed: 11/09/1988
• Issued: 02/25/1992
• Est. Priority Date: 06/28/1985
• Status: Expired due to Fees

• Current Assignee: ICI Australia Limited
• Original Assignee: ICI Australia Limited
• Inventors: Abouav, David M.
• Primary Examiner(s): Carone, Michael
• Application Number:
  US07/269,117
• Time in Patent Office: 1,203 Days
• Field of Search: 102/200, 102/202.5, 102/206, 102/220, 102/202.1, 102/215, 102/217, 102/218, 102/301, 102/311, 102/331, 102/332
• US Class Current: 102/200
• CPC Class Codes: F42B 3/122 Programmable electronic delay initiators
• CPC Class Codes: F42C 15/40 wherein the safety or arming action is effected electrically
• CPC Class Codes: F42D 1/055 specially adapted for firing multiple charges with a time delay

Abstract

An actuator for use in conjunction with a detonator for blasting comprises electronic circuitry which on receiving input signals generates an output arm signal to arm a detonator, and then after a predetermined delay an output actuate signal to fire the detonator and an associated explosive charge. The delay is capable of being remotely and precisely set. The actuator is preferably used in conjunction with a control device which has a microcomputer whose memory contains arm and actuate codes and which has both arm and actuate keys. This microcomputer is such that the actuate key must be operated within a predetermined period after operation of the arm key, otherwise an actuate signal is not transmitted to the actuator.

Claims

1. An actuator for a detonator that explosively actuates using stored charge and is responsive to at least one predetermined digital input signal transmitted from a remotely-located control device comprising:

a housing adaptable to be placed in close proximity to said detonator;

means disposed in said housing for inputting said predetermined digital input signal from said control device;

means disposed in said housing for independently generating, on input of said predetermined digital input signal, an output arm signal that changes the state of said detonator from a disarmed state in which said detonator is incapable of being actuated regardless of stored charge used to cause explosive actuation of said detonator to an armed state; and

means disposed in said housing for independently generating, at a predetermined period after the input of said predetermined digital input signal, an output actuate signal that causes explosive actuation of said detonator.

2. An actuator according to claim 1, wherein the actuator and its associated detonator are in modular housings which are connectable together, the making of the connection establishing appropriate electrical connections.

3. An actuator according to claim 1, wherein said actuator includes a microcomputer with a memory that stores an arm code and an actuate code.

5. An actuator according to claim 3, wherein said predetermined period can be programmed into said microcomputer by inputting a delay calibrate input signal from said control device after said detonator is in place in a blasthole.

6. An actuator according to claim 3, wherein said microcomputer generates said output arm signal and said output actuate signal after said predetermined period by reference to said stored arm code and said stored actuate code.

7. An actuator according to claim 1, wherein the output arm signal and actuate signal comprise multi-bit digital codes.

4. An actuator according to claim 4, wherein said predetermined period can be programmed into said microcomputer.