Sequential blasting system

US5571985A · kind A · utility

Assignee

• Euro-Matsushita Electric Works Aktiengesellschaft · DE

Inventors

• Heinz Ritter · Schongau, DE
• Wolf Steinbichler · Bad Feilnbach, DE

Key dates

• Filing date: Apr 25, 1995
• Grant date: Nov 5, 1996
• Expiry date: Apr 25, 2015

Classification

• Technology area (CPC F): Mechanical Engineering; Lighting; Heating
• CPC primary: F42D1/055
• WIPO field: Other special machines
• WIPO sector: Mechanical engineering

Abstract

A sequential blasting system for use in particular in mining comprises a plurality of detonator stages S1, S2, . . . , each of which contains a series circuit consisting of a thyristor T and a detonator means ZE, said series circuit being interposed between two supply leads A, O; B, 0. The signal voltage for the thyristor T in each stage is derived solely from the switching state of the thyristor T of the preceding stage. This causes activation to be transferred from stage to stage independently of the detonator means ZE, in particular irrespectively of whether or not a detonator has been attached and whether or not this detonator becomes highly resistive or not as it should upon being activated. This eliminates the errors that have occurred in known circuits. Upon firing the blasting system, such errors can cause the detonation to occur not only at the first detonator stage, but simultaneously at a location where a detonator is missing as well. In other cases, such errors terminate the detonating sequence at the site of an improperly functioning detonator and induce impermissible delays and thus considerably shorten the length of time between the electrical sequence and the blast,…