Abstract: A locking manhole cover which may be made of lighter weight material than conventional iron or steel manhole covers has a cover plate dimensioned to fit over a manhole opening. A cylindrical frame is attached to the underside of the cover plate and extends downwardly into the hole when the cover plate is in place. Diametrically opposed apertures are located in the side of the frame; and movable locking members are hingedly attached to the frame adjacent the apertures for pivotal movement through the apertures from a location within the frame to a location where a portion of the locking members engage the sides of the manhole in which the device is located. An operator is mounted inside the frame for effecting the pivotal movement of the locking members by means of an interacting cam or gear arrangement.

Abstract: A system for simultaneously lining and cleaning an existing sewer pipe, and for laying horizontal pipe without digging a trench, includes a planetary gear assembly mounted on a drilling rig. A liner pipe or outer pipe which is to be laid underground is placed over an inner auger, with the forward end of the liner pipe located behind the auger drill bit. The opposite end of the auger is attached to the sun gear of the planetary gear assembly; and the outer pipe is secured to the ring gear of the assembly. The auger is rotated in one direction, causing the outer pipe to rotate in the other direction; and the pipe and auger are pushed simultaneously through the pipe to be lined or through the soil. Once a section of auger and liner pipe have been pushed in place, the planetary gear assembly is disconnected from the auger and the liner pipe, new sections of auger and liner pipe are connected to the existing sections at one end, and to the planetary gear assembly at the other end.

Abstract: A mobile foxhole excavator (MFE) is mounted on a standard military vehicle for transport and positioning. The excavator is powered by a self-contained internal combustion engine, which powers a hydraulic system for positioning an auger mast in three mutually perpendicular planes (horizontal, vertical and lateral) to permit the auger to bore holes at any desired angle between vertical, downward, and horizontal, as well as boring at various overhead angles between horizontal and near vertical. A single hydraulic motor is used to operate the boring auger, as well as various hydraulic cylinders to effect the desired positioning of the auger mast.