Abstract: A combination for making up and breaking out pipe at an oil rig site includes a torque module and at least one pipe clamp apparatus. The torque module includes a pair of hydraulic motors, a torque transmission driven by the motors, a herringbone gear segment driven by the transmission to rotate the torque module, and a pair of clamp cylinders actuated by the transmission. The at least one pipe clamp apparatus is actuated by at least one of the clamp cylinders to apply a uniform gripping load around a pipe that is pipe diameter independent.

Abstract: A construction apparatus having an extendable mast with an upper mast element longitudinally displaceable relative to a lower mast element. A linear drive displaces the mast elements relative to each other, and has an upper drive part linearly actuable relative to a lower drive part of the linear drive, and a locking device for locking the two mast elements in an extended mast position. The upper drive part is fixable to the upper mast element, the lower drive part of the linear drive is displaceable longitudinally of the lower mast element and a securing device is provided on the lower mast element, with which the lower drive part is releasably securable to the lower mast element for displacement of the upper mast element. A method for operating a construction apparatus with an extendable mast can be carried out with a construction apparatus in accordance with the invention.

Abstract: This invention is a machine for ventilating roof decks which, without such ventilation, entraps moisture which leads to reduced insulating capacity, deterioration and the like. This ventilating device includes a mobile carriage, an extensible lift and an impact head along with associated operating mechanisms.

Abstract: A device in rock or earth drilling apparatus for rotary drilling including an axially stationary chuck (21) and an axially movable chuck (27) which is rotated by a reversible pressure fluid driven rotary motor (32) having a pressure fluid supply conduit for each direction and which is moved forwards and backwards by a reversible pressure fluid driven feed motor (17) having a pressure fluid supply conduit (18, 19) for each direction, the chucks being actuated to withdraw from or insert in a drill hole a drill string (23) composed by a number of threaded string elements and (are also actuated) to make or break the joints between the string elements.

Abstract: An improved shaft drill break-out system is disclosed that utilizes three separate out-put torques for the power swivel used to break-out, make-up and rotate the drill stem and attached drill bit for earth boring. When removing drill stem from the hole, the power swivel is tightened to the upper end of the drill stem with the largest torque. Thus, when the upper section of drill stem is lifted for breaking the bottom connection from the next lower section of drill stem, it is assured that this bottom connection will be broken since when going in the hole this connection was made-up with the intermediate torque. The lowest torque is used for drilling. As a consequence, sufficient torque for break-out is assured with proper selection of each of the three torques. Additionally disclosed are break-out arms and a slip assembly adapted for selected engagement with vertical slots in the drill stem to facilitate make-up and break-out.

Abstract: A system for use in the make-up or break-out of drill stem members of earth boring machines having a hydraulically operated power swivel to rotate the drill stem and hydraulic cylinders to raise and lower the swivel. A first, variable volume pump supplies fluid to the hydraulic cylinder through a four-way valve. A servo pump controller, connected with this valve and operable by variable resistors, establishes the linear make-up and break-out speeds for the power swivel. A second, variable volume and reversible pump supplies fluid to the power swivel means. A second servo pump controller, connected with the second pump and operable by variable resistors, establishes selected linear rotational travel speeds for the power swivel. Make-up torque is controlled by an electrical solenoid activated pressure compensator connected with the second pump, and linear speed is similarly controlled.