Abstract: Embodiments may take the form of a perforating gun of modular assembly. The perforating gun may include at least one centralizing member at an interface between a loading tube and a carrier. Among modular components, the gun may also include an initiator assembly module that is electrically coupled to a modular feedthrough with a connector. The insert and the centralizing member may enhance axial cohesiveness of the modular gun. A shock absorbing mount may be located within the carrier and may receiving the initiator assembly module to provide added axial cohesiveness to the modular gun.

Abstract: An acoustic isolation device includes a sleeve having a length, central axis along the length, a first end and a second end and an interior between the first end and second end, the cylindrical sleeve further comprising at least one resiliently deformable section between the first end and the second end along a least a portion of the length of the cylindrical sleeve allowing the cylindrical sleeve to be deflected, and a tab stop structure positioned along the length of the deformable section of the cylindrical sleeve and having at least one tab stop positioned in the sleeve, the cavity providing a gap around one or more sides of the at least one tab stop, wherein the at least one tab stop is movable within the cavity as the sleeve is deformed but restricts the sleeve from being deformed by more than a predetermined amount or estimated amount.

Abstract: An acoustic isolation device includes a sleeve having a length, central axis along the length, a first end and a second end and an interior between the first end and second end, the cylindrical sleeve further comprising at least one resiliently deformable section between the first end and the second end along a least a portion of the length of the cylindrical sleeve allowing the cylindrical sleeve to be deflected, and a tab stop structure positioned along the length of the deformable section of the cylindrical sleeve and having at least one tab stop positioned in the sleeve, the cavity providing a gap around one or more sides of the at least one tab stop, wherein the at least one tab stop is movable within the cavity as the sleeve is deformed but restricts the sleeve from being deformed by more than a predetermined amount or estimated amount.

Abstract: A wellbore perforating device includes at least one perforating charge and an initiator. The initiator can include a ballistic train adapted to fire the at least one perforating charge. The ballistic train can include a detonator and a detonator cord. A ballistic interrupt shutter can be disposed between the detonator and the detonator cord. The ballistic interrupt shutter can prevent firing of the detonator cord.

Abstract: Embodiments may take the form of a perforating gun of modular assembly. The perforating gun may include at least one centralizing member at an interface between a loading tube and a carrier. Among modular components, the gun may also include an initiator assembly module that is electrically coupled to a modular feedthrough with a connector. The insert and the centralizing member may enhance axial cohesiveness of the modular gun. A shock absorbing mount may be located within the carrier and may receiving the initiator assembly module to provide added axial cohesiveness to the modular gun.

Abstract: A wellbore perforating device includes at least one perforating charge and an initiator. The initiator can include a ballistic train adapted to fire the at least one perforating charge. The ballistic train can include a detonator and a detonator cord. A ballistic interrupt shutter can be disposed between the detonator and the detonator cord. The ballistic interrupt shutter can prevent firing of the detonator cord.

Abstract: A truck cab has a side door (14) via which a person enters and exits the cab by ascending and descending steps (22, 24, 26; 40, 42, 44) on a side of the truck. At least one of the steps is selectively positionable to a deployed position for use by a person ascending or descending the steps and to a non-deployed position when the truck is to be driven. The deployed position is relatively more outboard on the side of the truck than the non-deployed position.

Abstract: A truck cab has a side door (14) via which a person enters and exits the cab by ascending and descending steps (22, 24, 26; 40, 42, 44) on a side of the truck. At least one of the steps is selectively positionable to a deployed position for use by a person ascending or descending the steps and to a non-deployed position when the truck is to be driven. The deployed position is relatively more outboard on the side of the truck than the non-deployed position.