Abstract: In the present apparatus, a system converting stress in a structural member into strain by positioning a body of lasing material (creating a coherent beam) on a structural member. The body has parallel end faces. One is opposite a mirror attached to the structural member. The member strain varies laser cavity spacing and modulates the laser beam as a function of strain.

Abstract: A reciprocating electric motor for wells includes a stator comprising a stack of coil groups surmounted by an annular power pack, the whole being mounted on a non-ferromagnetic tube and potted and slipped into a tubular ferromagnetic housing, the coils being helically wound strips of conductive material with their outer ends folded down to extend paraxially and their inner ends folded radially thereacross and then down paraxially to provide connections between like coils in each group forming a plurality of sets for simultaneous energization, and an armature extending through the stator coils and annular power pack for reciprocation therewithin, the armature including alternating ferromagnetic and non-ferromagnetic sections.

Abstract: A reciprocating electric motor employs plural motor stator modules each including a group of coils selectively energized in subgroups to produce a magnetic field sweeping from one end of the group to the other and then repetitively from the same one end to the other always in the same direction until a number of ferromagnetic non-ferromagnetic armature sections each equal in length to the length of the stator modules and equal in number to the stroke of the motor divided by the length of each section has passed the stator module and thereafter the sequence of energization is reversed to move the armature a like distance in the opposite direction, the several coils of each group being electrically connected in a set each of which has its own power supply, the power supplies being collectively controlled by a microprocessor.

Abstract: A reciprocating electric motor-pump assembly for wells lifts well fluid on downstroke of the motor-pump assembly, and with the motor above the pump the well fluid is conducted from below the motor to above the motor via a flow passage through the motor armature, which is tubular.