Timing apparatus
US5282421A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 28, 1992 |
| Grant date | Feb 1, 1994 |
| Priority date | — |
| Expiry date | Jul 28, 2012 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF42D1/055
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
The invention relates to a blasting apparatus for activating a plurality of electrical detonators after predetermined time delays. The blasting apparatus includes a plurality of remote electrical delay devices. Each device is linked to a detonator, and is arranged to be serially programmed with a timing signal, which originates from the central control unit and which determines the time delay. A bidirectional signal harness, having ends which terminate at I/O ports in the control unit, serially links the delay devices to the control unit. In the event of a fault of discontinuity occurring in the harness prior to programming of the delay devices, the discontinuity is detected and the direction of programming along the bidirectional harness is reversed so that those delay devices which, due to the break, cannot be programmed in the initial direction, are programmed with timing signals travelling along the signal line in the opposite direction. The invention extends to a method of activating a plurality of electrical detonators, as well as to the individual delay devices forming part of the blasting apparatus.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.