Abstract: A pressure-driven cylinder having a piston sliding within a sealed housing chamber between a pair of opposed side-end walls in a piston chamber. At least one chamber wall has a moveable portion of an end wall integrally connected to and axially spaced away from a pressure-driven face of the piston by an integral connector point that is much smaller in area than the piston's pressure face. That moveable wall portion acts as an integrally connected piston follower that has its own extended surface area that is progressively introduced into the presure chamber as the piston slides in order to reduce the required volume of pressurized driving fluid in the piston chamber. A chamber for the follower itself is sealably isolated from the piston chamber so that no driving fluid backs into the follower chamber. Both the end wall/follower and the piston reciprocate together.

Abstract: Apparatus for driving earth entering elements such as drills and casings which can be threaded together to form strings has a column to be erected in a wanted position. The column is provided with a unit moveable lengthwise thereof between upper and lower limits. The elements have two vertically spaced pairs of transversely aligned lugs with the lugs of the two pairs vertically aligned. The unit is provided with clamping jaws which positively grip the driving end of an element and prevent its turning relative to the jaws only if the element is in the driving axis of the unit in a predetermined position such that its lugs can be caught when the jaws are closed. A loader carries a plurality of elements which are held in sockets parallel to the driving axis and is moveable between an inoperative position and a position in which a selected element is positioned in the axis and which will then have its lugs appropriately positioned for locking engagement by the jaws.

Abstract: A moveable flood barrier requires a permanent channel in the path of expected flood waters and is normally closed by a removeable cover. The barrier consists of a series of units dimensioned to be removeably seated in the channel and detachably interconnected. Each unit includes at least one panel disposed to face flood waters and a reenforcement to which the panel or panels are attached. The junctions between panels are sealed and seals extend lengthwise of the barrier and are secured to the panels thereto and detachably secured to the channel wall first in the path of the flood waters. Where required, a brace for each unit is detachably secured thereto and to a permanent normally covered socket on the leeward side of the channel.

Abstract: A pulling device for use in withdrawing well points and the like comprises a boom, a column fixedly mounted at an outer end of the boom, apparatus for adjustable positioning of the column over a well point to be withdrawn from the ground and disposing it vertically for pulling without jamming. A gripping carriage is vertically moveable on the column. The carriage carries a first, fixed jaw in alignment with the center plane of the column comprising first and second vertically spaced apart first jaw elements and a second jaw comprising first and second vertically spaced apart second jaw elements. The second jaws are moveable relative to the first jaws so as to grasp the top of the well point to be pulled between them. Hydraulic cylinders power the jaws and raise the carriage so as to pull the gripped point.