Abstract: One or more apparatuses are described for drilling, and related methods. The apparatus can include a mast articulation mechanism supported by a base structure, an elongated mast, and a mast actuator.

Abstract: One or more apparatuses are described for drilling, and related methods. The apparatus can include a mast articulation mechanism supported by a base structure, an elongated mast, and a mast positioning actuator comprising a mast actuator that may be supported by a removable mounting element when in a short mast configuration. The method for drilling can include drilling a borehole using the apparatus.

Abstract: A Kelly bar apparatus includes a plurality of concentric tubes in a telescoping arrangement having either a locking feature provided by a series of keys and notches that interlock selectively, or one or more blocking tabs that prevent complete telescopic extension of at least one of the tubes when the tubes and associated keys are in an unlocked position, or both. Related subterranean bore drilling systems and drilling methods are also described.

Abstract: An underreamer includes a housing and a plurality of underreamer doors, each including a toggle mechanism for selectively extending and retracting the doors. Upon activation of the toggle mechanism thereby extending the doors, the doors are pivoted outwardly from the housing and the tops of the doors are simultaneously moved downwardly. In this manner the overall vertical height of an underreamer adapted to form a given diameter excavation may be substantially reduced.

Abstract: A core barrel comprises an elongate hollow cylinder having a substantially uniform diameter throughout its length and having apparatus at one end thereof for connection to a kelly. The opposite end of the core barrel cylinder is provided with a plurality of circumferentially spaced apart tooth receiving notches each rectangular in shape and characterized by opposed edges spaced apart a predetermined distance. A core barrel tooth is received in each of the notches of the cylinder, and each tooth comprises a central body portion having spaced apart surfaces which engage the opposed edges of the notch. Opposed lateral flanges extend in the forward and rearward directions from the central body portion of each core barrel tooth along the inner and outer surfaces of the core barrel cylinder. Bifurcations extend from one end of the opposed lateral flanges of each core barrel tooth along the inner and outer surfaces of the core barrel cylinder.

Abstract: A core barrel comprises an elongate hollow cylinder having a substantially uniform diameter throughout its length and having apparatus at one end thereof for connection to a kelly. The opposite end of the core barrel cylinder is provided with a plurality of circumferentially spaced apart tooth receiving notches each rectangular in shape and characterized by opposed edges spaced apart a predetermined distance. A core barrel tooth is received in each of the notches of the cylinder, and each tooth comprises a tooth body having spaced apart surfaces which engage the opposed edges of the notch. Bifurcations extend from the tooth body of each core barrel tooth along the inner and outer surfaces of the core barrel cylinder. Aligned holes are formed through the bifurcations of each tooth and through the portion of the cylinder extending therebetween, and roll pins are utilized to secure the core barrel teeth in the tooth receiving notches of the core barrel cylinder.