Patent ID: 7536742
Filing Date: 2009-05-26
Classification: B08B,F16L

Abstract:
1. An apparatus for pushing a dual diameter pig through a conical reducer attached to a pig trap and into a pipeline, the apparatus comprising: a frame configured to support a pig longitudinally such that the pig can move forward along the frame, and having a front end adapted for attachment to the pig trap; at least one leg supporting the frame such that a vertical position of the frame can be adjusted to align a front end of a pig supported on the frame with an open end of the conical reducer; an extendable actuator supported on the frame such that the actuator is rearward of, and substantially aligned with, a pig supported on the frame; and an actuator control operative to extend the actuator such that a front end thereof moves forward with respect to the frame and into contact with a central portion of a rear end of a pig supported on the frame, and operative to retract the actuator; a lock operative to selectively lock the actuator to the frame at a plurality of lock locations between the front end of the frame and the rear end thereof, and wherein the lock locations are separated by a distance that is less than a stroke of the actuator.