Abstract: An apparatus and method for centrally installing a shoring column into a predrilled hole includes a ring-shaped supporting structure which fits into the hole and includes a central opening large enough for the column. Clamp elements attached to the supporting structure clamp the column. A plurality of centralizing piston and cylinder units attached to the supporting ring extend outwardly to engage the side of the ground hole to centralize the support structure and column in the hole. The elements associated with the supporting structure are controlled remotely from control elements located at ground level outside of the ground hole.

Abstract: This relates to a device for pulling together sewer pipes and other large diameter pipes. The device includes a mobile pulling unit which is preferably mounted on wheels and may be driven through the large diameter pipes. The mobile pulling unit has a pulling cable which extends from a lower portion thereof. A support system is pivotally mounted on the pulling unit and is preferably in the form of an elongated lever including a lower lever arm and an upper lever arm with the two lever arms being disposed in angular relation with respect to each other and carrying shoes for engaging lower and upper surfaces of a pipe in which the pulling unit is mounted. A pressure applying device extends between the pulling unit and the upper lever arm so as to tilt the support means and effect the anchorage thereof in the pipe.

Abstract: An extraction mechanism which may be utilized for the purpose of pulling sheeting elements after they have been utilized in shoring ditches. The apparatus includes a tower which may be seated firmly on the ground and have the top end thereof positioned by means of a boom of equipment utilized in the normal trenching operation. A series of cables and pulleys are provided with there being a hydraulic cylinder for effecting the relative movement of certain of the pulleys so as to foreshorten the cable or cables and thus produce the necessary pulling effort. The system includes winding reels to take up the pulled cable slack and clamp means for preventing movement of the cable first in one direction and then the other direction in accordance with the direction of movement of the fluid cylinder.