Locking assembly apparatus for pump systems, and related methods

A locking assembly for a piston apparatus, comprising:

• an outer housing;
• an elliptical shaped actuator wedge comprising four rounded outer edges;
• an actuator rod having a rectangular cross section disposed through the actuator wedge;
• an actuator nut disposed at a first end of the actuator rod;
• a first ram disposed in the outer housing and disposed on a first side of the actuator wedge, the first ram comprising:
• a first ram head, the first ram head comprising a first inward surface and a first shoulder surface opposing the first inward surface, wherein the first inward surface faces the one or more outer surfaces of the actuator wedge, and
• a first ram rod;
• a second ram disposed in the outer housing and disposed on a second side of the actuator wedge, the second ram comprising:
• a second ram head, the second ram head comprising a second inward surface and a second shoulder surface opposing the second inward surface, wherein the second inward surface faces the one or more outer surfaces of the actuator wedge, and
• a second ram rod;
• a first spring disposed about the first ram rod and abutting against the first ram head;
• a second spring disposed about the second ram rod and abutting against the second ram head;
• one or more first rollers disposed partially in the first inward surface of the first ram head and in contact with the actuator wedge;
• and
• one or more second rollers disposed partially in the second inward surface of the second ram head and in contact with the actuator wedge, wherein the one or more first and second rollers are closer to the rectangular cross section of the actuator rod when the locking assembly is in an unlocked position than when the locking assembly is in a locked position.