Explosive carrier end plates for charge-carriers used in perforating guns

In explosive carrier end plates for charge-carriers utilized in guns for the perforation of petroleum producing wells, wherein each gun is vertically coupled with similar guns inside the casing of the well, and each gun is a hollow cylinder in which is located a corresponding carrier that holds explosive shaped-charges;

• and wherein the carrier is a tube having an outer diameter smaller than the inner diameter of the hollow cylinder, and having multiple peripheral mountings for radial placement of the shaped-charges which are in contact with a detonation cord that contacts an electrically-operated detonator;
• and wherein each carrier has mounted on the upper end thereof an upper end plate and on the lower end thereof, an insulating end plate with a retractable electrical spring contact capable of pushing upwards;
• the improvement comprising:
• wherein each end plate comprises a cylindrical piece, each cylindrical piece having a cavity and a dominant diameter with a cylindrical surface whose diameter is intermediate to the inner diameter of the hollow cylinder and the outer diameter of the carrier tube, each cylindrical piece having a peripheral means for centering the carrier, a central opening passage, and a concentric annular rabbet that reciprocally fits with a corresponding end of the carrier;
• wherein
• the cylindrical piece of each end plate having at least three straight peripheral recesses parallel to the axis of the cylindrical piece and separated from each other in an equiangular fashion and extending radially in the wall formed by an end of the cylindrical piece and provided for the passage of a respective concentric annular rabbet that fits in the corresponding end of the carrier;
• a “J”-shaped metal centering clip provided at each recess, having a substantially straight long arm with an elbow abutment for anchoring in a respective window of the cylindrical wall of the carrier and a minor curved arm with a terminal tab to hook on the edge portion of the outer wall of the cylindrical piece that matches the straight section of the recess;
• said curved arm being of an elastic metal for self-centering the end plate and being tangentially in contact with an inner face of the wall of the gun, and providing electric contact between said carrier and the gun;
• the cylindrical piece of each end plate having a central opening axially fitted with a single removable insert and presenting reciprocal guiding and positioning means that is congruent between the walls of said cavity and the corresponding insert;
• and the peripheral cylindrical wall of the cylindrical piece having means for positioning the cylindrical piece with the wall of the gun.