Abstract: A rotary drill bit comprises a bit body having a leading face and a gauge region, a number of blades on the leading face of the bit body, and a number of cutting elements mounted along each blade. A passage in the bit body supplies drilling fluid to nozzles in the leading face of the bit body for cooling and cleaning the cutting elements. Each nozzle is so oriented, and the surface of the bit body in the region in front of each blade is so shaped, as to promote a vortex flow of drilling fluid around said region, with part of the periphery of the vortex extending across the cutting elements on the blade, so that fluid in the periphery of the vortex passes across the cutting elements mounted on each blade before escaping through an exit channel in the gauge region.

Abstract: A full bore drag-type well drilling bit comprises a bit body having an operating end face defining a plurality of upsets. Each of the upsets has a leading edge surface and at least one recess extending through the leading edge surface into the upset. The end face of the bit body further comprises a plurality of flow channels, each such leading edge surface having one such flow channel extending therealong and inset therefrom. At least some of the upsets have a plurality of such recesses spaced therealong. The bit body further has a plurality of circulation ports opening through its end face and a plurality of nozzles, each nozzle being mounted in a respective one of the ports. The number of nozzles is less than the number of flow channels. At least some of the nozzles communicate with more than one such flow channel, and the transverse cross-sectional flow area of each of the nozzles is substantially less than those of individual ones of the channels communicating therewith.

Abstract: The invention comprises a drag-type drill bit including a bit body adapted for rotative movement in a pre-determined direction in use and having an operating end face, and a plurality of cutting members mounted in the bit body. Each of the cutting members has a stud portion disposed in a respective recess in the bit body and defining the inner end of the cutting member, and a cutting face generally adjacent its outer end facing outwardly through the operating end face of the bit body and terminating in an outermost cutting edge. The centerline of the stud portion is rearwardly inclined, from the outer end to the inner end, with respect to the direction of movement in use, taken at the midpoint of the cutting edge, at a first angle from 80.degree. to 30.degree. inclusive. The cutting face is oriented such that the tangent to the cutting face at the midpoint of the cutting edge and in the central plane of the cutting member is disposed at a second angle, from 18.degree. to 75.degree.

Abstract: A full bore drag type well drilling bit including a bit body comprised of a generally non-frangible metallic material. The bit body has an operating end face defined by said metallic material to include a plurality of upsets each having a leading edge and at least one recess extending through such leading edge into said metallic material. The end face further includes a plurality of flow paths, each of the leading edges of the upset having one such flow path extending therealong and inset therefrom. At least some of the upsets have a plurality of such recesses spaced therealong. A plurality of circulation ports open through the end face of the bit body, the number of circulation ports being less than the number of flow paths extending along the leading edges of the upsets, and at least some of the ports communicate with more than one such path. The bit further comprises a plurality of cutting structures carried by the bit body.

Abstract: A rotary filing device wherein mounting strips adapted to receive a container for an item or items to be stored are linked together in an endless chain and supported at each end in common recesses in a frame such that the chain is movable by tilting successive strips to provide access to each container in turn. The frame carries projections which are adapted to interlock with projections on an identical element or on a mounting bracket whereby a plurality of devices can be secured together and/or to a support. When the container is a tape cassette library case, the mounting strip may additionally be adapted to both the cassette case and the cassette itself, as desired. A spring loaded catch fitted in the recess to bear upon the ends of the mounting strips received therein, enables positive indexing and automatic resumption of a tidy equilibrium position, irrespective of the orientation of the device, in use.

Abstract: A rotary drill bit for use in subsurface formations includes fluid channels for the passage of drilling mud to remove cuttings. According to the invention to clear blockages there are only one or two unbranched channels for the passage of mud past the cutting elements and these are arranged in a spiral.