Abstract: An apparatus for remediating water wells comprises a plurality of retractable cutting blades suitable for cutting openings in a well casing. The retractable cutting blades and corresponding drive mechanism are organized to be lowered through a well casing. At certain depths, the retractable blades are extended to cut openings in the well casing. The apparatus also includes inflatable retention elements both above and below the retractable blades to create a fluid seal within the well casing. A solidifying, waterproof slurry is injected to flow through the openings via a slurry delivery mechanism, and thereby create a waterproof barrier outside the well casing at the level of a waterproof confining soil layer.

Abstract: An apparatus for remediating water wells comprises a plurality of retractable cutting blades suitable for cutting openings in a well casing. The retractable cutting blades and corresponding drive mechanism are organized to be lowered through a well casing. At certain depths, the retractable blades are extended to cut openings in the well casing. The apparatus also includes inflatable retention elements both above and below the retractable blades to create a fluid seal within the well casing. A solidifying, waterproof slurry is injected to flow through the openings via a slurry delivery mechanism, and thereby create a waterproof barrier outside the well casing at the level of a waterproof confining soil layer.

Abstract: A mechanical latch attachment (20) for a control relay (21) includes a mechanical latch movement (77), a solenoid (49), and a pair of contact cartridges (33) that are disposed in a housing (25). The wear-resistant latch movement (77) has a latch (95) with teeth (103) on one end that are engaged by a pair of pivotable, hooked pawls (105). The latch (95) is coupled to an operating plunger (79) through a contact actuator (82). The operating plunger (79) can be coupled to a conventional control relay (21), which moves the plunger (79) upon the closing of its relay armature (30) to actuate the contacts (35, 36) in both the relay (21) and the attachment (20) and to move the latch (95) to a position where it is restricted by the pawls (105). The restriction of the latch (95) holds the relay armature (30) closed and the contacts (35, 36) actuated even though the relay (21) is deenergized.