摘要:
A milling tool for forming recesses, such as an undercut in a borehole, in masonry, concrete and similar material structures includes a tool shaft with a bearing pin extending outwardly from one end of the shaft and with the axis of the pin offset eccentrically to the axis of the tool shaft. A freely rotatable annular milling head is positioned on and encircles the bearing pin. The outside surface of the milling head has cutting edge members.
摘要:
An upper stabilizer and a lower reamer are mounted on an integral or one-piece body adapter to be connected in a tubular drilling string for drilling well bores.
摘要:
A drill bit having a body segmented for convenient disassembly and transportation through underground passages and for subsequent assembly to drill large diameter holes. A stem serves as the driving means and has a threaded connector for attachment to drill pipe that rotates and forces the bit through the earth. A first, segmented cutter support means extends laterally from the stem. A bridge or collar is assembled coaxially over the stem and is secured to a second, segmented cutter support means. Pockets are formed in the first cutter means to receive the second cutter support means, each having surfaces to transmit torques and thrusts. This construction avoids large drilling induced stresses on the fastener means used to hold the separate cutter support means together in operation. For final and more rigid angular alignment of the segments, shims are received in machined grooves in the walls of the pockets to eliminate the necessity for accurately machining the entire surfaces of the walls. Fasteners then secure the shims and the segments in the assembled relationship.
摘要:
A rig for rotary drilling, in which a pilot drilling tool is disposed coaxially relative to the drilling string and side drilling tools are radially displaced with respect to the pilot drilling tool, with the side tools rotating freely and partially overlapping the pilot tool drilling tool and disposed above the latter in a body which is rigidly connected to the drilling string.
摘要:
A raise drill for enlarging a pilot hole into a larger diameter hole by disintegrating the earth formations surrounding the pilot hole is disclosed. The raise drill includes a main bit body having a plurality of cutters mounted thereon. The bit body is detachably secured to the drive stem to permit removal and replacement of the stem. The removable drive stem allows the raise bit to be transported through small drifts and helps extend the useful life of the raise bit. The drive stem extends through a central opening in the raise bit body and includes an upwardly facing shoulder for engaging the margin of the bit body about the opening. The drive stem further includes a plurality of tapered flat surfaces located about the periphery of the bottom end thereof. A plurality of bolted wedge blocks, attachable to the main bit body are provided to engage the tapered flat surfaces of the drive stem in order to urge the shoulder of the drive stem into locking engagement with the main bit body.
摘要:
A raise drill having a central drive stem to which a surrounding cutter mounting frame is attached, the cutter mounting frame supporting a plurality of rotary cutter units. One or more inboard cutter units each include a shaft and a rotary cutter journaled for rotation on the shaft. One end of the shaft is inserted in a bore extending into the side of the stem. A yoke member receives the outer end of the shaft. The yoke member is supported by a mounting block secured to the frame. The mounting block has first and second intersecting planar surfaces, the first surface extending substantially parallel to the axis of the bore and the second surface extending in an obtuse angle to the first surface facing the stem. The yoke member has a first surface which slidably engages the first surface of the mounting member, and a second surface spaced from the second surface of the mounting member, allowing axial movement of the cutter shaft into and out of the bore. A spacer or shim is inserted between the second surfaces after the shaft is inserted in the bore and bolts extending between the yoke and the mounting block pull the yoke against the mounting block and at the same time clamp the spacer in place.
摘要:
A bit is provided that includes a bit body defining a bit axis of rotation. Primary cutter means are positioned on the bit body for disintegrating the formations out to a first radial distance from said bit axis of rotation. Secondary cutter means are adapted to be connected to the bit body and selectively located in a first position for cutting between said first radial distance and a larger second radial distance and selectively located in a subsequent position between said first radial distance and an even larger subsequent radial distance. Expansion means are provided to be located between said secondary cutter means and said bit body for locating said secondary cutter means in said subsequent position.
摘要:
A bit for drilling large-diameter holes. Cutters are arranged in a staged configuration around a central shaft. The innermost cutters are the same large cutters used at other locations on the bit allowing complete interchangeability. The innermost cutters are turned inward. This reduces the uncut bottom next to the pilot hole and provides a stronger bit because the central shaft has not been weakened by milling or other operations.