A roller cutter drill bit comprises a body having a journal, a roller cutter, bearing means for rotatively mounting a roller cutter on the journal and a part of said bearing means including a hard, tough metal bushing with a lubricant metal coated thereon, and positioned between the sleeve and the journal and between the sleeve and the roller cutter to prevent galling.

A bit holder consisting of steel, said bit holder comprising a bore for accommodating the bit shaft and being welded to the cutting head of a cutting machine, characterized in that the bit holder consists of a part of heat-resistant steel of high strength and of a foot consisting of an unalloyed or low alloy steel of good weldability and being welded to said foot over the whole contacting area. In making the holder a blank corresponding to the part accommodating the bit shaft is over the whole c...

A drill bit for drilling holes of a given diameter in wood or similar material comprising a drill body having a series of stepped cylindrical portions increasing in diameter from the small entry end of the drill to the full diameter of the hole to be drilled whereby the drill body is of generally conical shape. Each of the cylindrical portions extends in a helical direction, and a single flute extends generally lengthwise of the drill body to provide cutting edges for the cylindrical portions an...

A diamond drill coring bit having an annular crown and inner and outer concentric side surfaces. The crown is formed from a number of radially extending composite segments spaced apart circumferentially by a circumferential spacer material, all integrally bonded together. Each composite segment consists of a number of diamond impregnated segments spaced radially from each other by a radial spacer material. The diamond impregnated segments have greater abrasion resistance than that of the radial ...

A drill bit having a central shank having an "S" shaped cutter integrally formed on or detachably secured to the shank. A collar is detachably secured to the shank above the cutter and is keyed to the cutter to prevent rotation of the collar. A generally flat secondary cutter is secured to the collar and has a plurality of depending cutter elements on the peripheral edge thereof as well as a plurality of radially extending chisel cutters depending therefrom.

A new and improved drill bit for connection on a drill string has a hollow tubular body with an end cutting face and an exterior peripheral stabilizer surface with cylindrical sintered carbide inserts positioned therein. Nozzle passages extend from the interior of the bit body through the cutting face, preferably at an angle of about 10.degree.-25.degree. relative to the longitudinal axis of the body, and consist of a passage in the bit body and a removable and interchangeable nozzle member. The...

A plurality of cutting plates are mounted in a recess forming a mouth at one end of a drill bit and each cutting plate has a plurality of cutting edges. The drill bit mouth provides chip removal. In the cutting position, the cutting plates are arranged in a plane extending in the direction of the axis of rotation of the drill bit and the cutting edges are arranged in a step-wise manner. The cutting plates can be turned for arranging different ones of the cutting edges in the cutting position. Th...

Bit for drilling wood or the like consisting of a spade from which extends a centrally-located point, the point being provided with a groove defined by two plane surfaces extending at an obtuse angle.

A bit synchronizer for T-4 fiber optic data communication environments is configured of an input buffer amplifier to which the data to be regenerated is applied. The input buffer provides isolation between upstream signal processing circuitry and a bit rate generator coupled to the output of the buffer. Also coupled to the buffer output is a bit decision circuit essentially configured of a limiter and output flip-flop. The bit rate generator employs a limiter and dual delay logic circuitry conne...

A drill bit having a generally cylindrical body with a working end and flutes extending along the body. The working end is formed with a central work-engaging point and a pair of slitting spurs spaced outwardly from the point adjacent edge margins of the body. Convexly contoured portions interconnect the point and spurs to permit sharpening with a round file.