Abstract: A detonating device principally intended for detonating an explosive charge in a well or borehole, and of the type which is actuated by pulling upwardly on a non-electrical line also used to lower the device into position. The device includes self-contained time-delay circuitry which requires a sustained mechanical actuating pull on the line for some predetermined time before an attempt is made to detonate the explosive. The circuitry includes a command switch actuated by pulling on the line, and a safety switch which must be closed before the command switch is closed, either manually or by hydrostatic pressure in the borehole. The circuitry locks in a safe condition if the command switch is closed first, or if one attempt has been made to fire the explosive, whether successful or not, thus allowing removal or repositioning of the device with complete safety.

Abstract: The device has a hollow housing having made therein a chamber adapted to accommoate an explosive charge, separated by a partition made of an elastomeric material for sealing the chamber from the cavity of the housing, communicating with the hole through lateral apertures in the housing. The device further includes a stem of a diameter that is lss than that of the rest of the housing, preferably threadedly secured to the bottom face of the housing. The stem has cut therein axial and radial passsages establishing communication between the cavity of the housing and the external lateral surface of the stem. A ring of an elastomeric material is received about the stem so that it closes off the openings of the radial passages in the external lateral surface of the stem.

Abstract: A seismic explosive charge loader and anchor is disclosed for loading and anchoring explosives in conventional containers, such as cylindrical packages and cans provided with projecting circumferential rims. The loader includes a first tubular member having an upwardly facing internal recess of sufficient diameter to loosely receive a loading pole or loading weight, and a second tubular member having a downwardly facing internal recess of sufficient diameter to fit about and receive the explosive container. A plurality of inwardly and upwardly tapered resilient gripping ribs are disposed in the internal recess and are arranged to grip smooth sides of the cylindrical explosive container and thereby securely hold it in the loader. The ribs are provided with an internal and circumferentially extending groove which receives and grips the circumferential rim or projection of the can type explosive containers.