Abstract: A small detonating device such as a rifle, pistol or shotgun primer or percussion cap is employed to provide gas and/or hydraulic pressure for the testing of the relative strength of articles such as plastic containers, sheet, tube and the like.

Abstract: A reciprocating sharpener includes a plastic or metal housing mounted on a rigid base. Each of four, thin, flat, rectangular steel springs has one of its edges fixedly secured to the base. The opposite edge or free end of each of the steel springs is fixedly secured to one end of one of two elongated armatures or carriage members that are mounted in the sharpener in a parallel, coplanar condition. The armatures include upper, unobstructed surfaces with abrasive material of the type used for grinding or sharpening metal affixed thereto. Each armature further includes a laminated, iron, armature core fixedly mounted thereto. A laminated, iron, stator core and field coil are fixedly mounted on the base. The two armature cores are physically spaced on opposite sides of the stator core to cause the armature cores to move toward the stator core and each other upon the energization of the field coil by periodic pulses of electric current.

Abstract: A grounded surface distribution apparatus and system is provided including elastomer encapsulated cable terminals, joints, taps, load-break switches, current limiting fuses and surge protectors, each enclosed completely within a metal sheath combined in various arrangements to perform operational functions required in loop and radial underground distribution systems. The cable terminals include a soft dielectric filler making a void-free interfacial engagement with the surface of a hard dielectric filler of a mating component. To provide for breaking a coupling under load, an arc-quenching follower is retractable into an axial cavity in the coupling components of the system and projectable therethrough upon breaking of the circuit and disconnecting of the components to provide an improved arc-quenching function. Thus, there is provided an underground system having security, operational safety and convenience.