The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 10, 1989
Filed:
Jul. 01, 1987
Stafford A Smithies, Pretoria, ZA;
Raymond C Atkins, Pretoria, ZA;
Gernal Mining Union Corporation Limited, Johannesburg, ZA;
Abstract
System for the electrical sequential initiation of explosions comprising a series of initiating modules connected to one another and connectable to a power supply, and a corresponding series of electrically actuable initiators. Each initiating module is connected to an initiator and embodies a non-latching switch for actuating the initiator associated with that initiating module. The non-latching switch comprises a solid state electronic device having an emitter, a gate and a collector, and comprises a short circuit between the gate and the emitter for holding the device in an 'off' state to a voltage applied to the collector. The device also comprises an open circuit between the gate and the emitter for turning the device 'on' to a voltage applied to the collector, while a diode integrated on the device blocks a reverse supply voltage. The non-latching switch of each initiating module save the first in the series is connected to the initiator associated with the preceding initiating module in the series. The arrangement is such that, in operation of the system, the non-latching switch of each initiating module is disabled until the initiator associated with the preceding initiating module in the series has been actuated by that initiating module. The initiating modules in the series are actuable sequentially by the power supply so as to sequentially initiate the series of initiators.