Abstract: A milling tool 8 includes a tool holder 10 for housing multiple thread cutting inserts 24 for precise milling of threads on a workpiece. The tool holder 10 is rotatable in an orbitable path spaced radially from a milling axis and is simultaneously rotatable about its own axis for repeatedly bringing each of the cutting inserts into engagement with the workpiece. Each cutting insert is precisely positioned within the tool holder by a stop surface 62 located at an axially rearward end of an insert cavity 28 in the tool holder. An axially elongate tool holder groove 32 is provided in communication with a side face of the generally rectilinear insert cavity. Each cutting insert defines a substantially rectangular plate, an end face for mating engagement with the stop surface 62 and an axially elongate insert groove 26 extending from a corresponding side face on the rectangular plate.

Abstract: A unitary bore forming and threading tool for producing a variety threaded bores having chamfers and counterbores without a need for tool changes. The improved took preferably includes a shaft of predetermined axial length and having proximal and distal ends, a shank located adjacent the proximal end, a holemaking element located adjacent the distal end, and a threadmill portion located axially between the bit and the shank. The holemaking element further includes a chamfering surface and an end cutting surface. The disclosed tool and method enable creation of a variety of bores such as chamfers, counterbores, and threaded bores by producing bore portions of selectively determined distinct diameters by sequentially axially feeding the tool into the workpiece along distinct tool paths without changing tools. If desired, one or more of the bore portions can be threaded with the threadmill by moving the threadmill in a selectively determined helical or nonhelical path.

Abstract: A threaded hole (20) in a workpiece (22) is formed by rapidly spinning an elongated tool (24) having a drill point (64) at one end, at least one longitudinally extending flute (80) having thread milling faces (84) for milling the thread to be formed, and wherein the tool (24) is first moved axially to carry the drill point (64) against and into the workpiece (22) to form a hole (66), then is displaced radially a distance equal to the thread depth to be formed, then is moved orbitally around the hole (66) to mill threads therein, then is displaced back to the center of the hole (20) and then is retracted from the hole (20). To form a helical thread in the hole (20), the tool (24) is shifted axially one thread pitch during the orbital movement. A thread milling drill head (26) is disclosed for chucking the tool (24) and shifting it through the aforesaid movements.

Abstract: A combination tool is disclosed for drilling a hole in a workpiece on the inward feed of the tool and for threading the hole during retraction of the tool. The tool that has a straight body with a drill point at the forward end, a shank at the rearward end and a thread-form mill between the drill point and the shank.

Abstract: In a numerical control machining system, a leftover area on a work produced by cutting the work with a larger diameter ball end mill is cut with a small diameter ball end mill. When the cutting trajectories of the small diameter ball end mill are determined, the leftover portions are identified in the directions of the cutting trajectories for the larger diameter ball end mill which are set at regular pitches and reference cutting trajectories for the small diameter ball end mill which are the cutting trajectories when cutting the leftover portions with the small diameter ball end mill in the direction of the cutting trajectories for the larger diameter ball end mill are obtained.

Abstract: Feed screws are used for container filling machines in order to separate a series of approaching containers at a specific distance from each other. Feed screws for non-rotationally symmetrically shaped containers are milled with a milling tool rotating at a high rpm, the shaft of which is arranged parallel to the longitudinal axis of the feed screw that rotates at a lower rpm. To avoid feed screw flank errors, the rotating milling tool is moved up and down in an oscillating manner, so that a milling tool can be used, the contours of which agree exactly with the associated cross sectional area of the containers which are to be handled. The first shaft of the milling tool is attached to a sliding carriage, which is movably guided in an upward and downward direction by means of a crank mechanism.

Abstract: In superfinishing a Gothic-arch-shaped groove of a nut by using a superfinishing stone attached to the tip end of an oscillation arm while oscillating the superfinishing stone about the oscillation axis and, at the same time, moving the superfinishing stone in the longitudinal direction of the Gothic-arch groove, the oscillation axis is inclined by a predetermined angle with respect to the longitudinal direction of the Gothic-arch groove. The shape of the cross section of the Gothic-arch groove orthogonal to the oscillation axis is regarded as a single circular arc and, thus, both flanks of the Gothic-arch groove can be superfinished simultaneously.

Abstract: A screw cutting method for use with a numerically controlled machining system is improved by enabling finer finishing of the final screw surface. The invention allows the removal of scars formed during rough machining by offsetting the position of the rough machining passes in the direction of screw cutting, i.e., in the direction of movement of the tool during cutting, so that during the final finishing pass, more material is removed from the screw surface opposing the cutting direction. Surface finish is further improved by specifically controlling the cutting depth in the cutting passes just preceeding the final cutting pass.

Abstract: In the thread cutting method according to the present invention, the cutting amount S in each of the thread cutting operations from the second thread cutting operation to the (N-1)th thread cutting operation can be made less than and closest to the allowable cutting amount S.sub.p in each of the thread cutting operations by respectively determining as the cutting amount S.sub.1 in the first thread cutting operation and the cutting amount S.sub.n at a cutting depth which corresponds to the bottom of thread the values which are less than and closest to the allowable cutting amount S.sub.p obtained at the two cutting depths. In consequence, wear of the tool can be reduced and the time required for the thread cutting process can be shortened while the thread cutting accuracy can be maintained high by determining either of two equations from the prerequisites and the processing conditions and then by designating the equation to be adopted.

Abstract: For machining male or female screws, especially of considerably large size diameter, variable pitch or tapered, as desired, a machining center is used which is composed of a work table mounting the work fixedly thereon, and a rotatable machining spindle exchangeably fitted with a thread-cutting tool. Axial feed and rotational speed of the spindle are driven by respective drive motors. In addition, the work table is fed bilaterally on a plane perpendicular to the axis of the spindle by respective feed motors. All these four motors are controlled synchronously by respective controllers which are subjected to control by a single parent numerical controller.

Abstract: A method of machining a member included a screw-shaped portion which is used when the member is ground at the screw-shaped portion by means of a machine tool, in particular, a grinder. A configuration of the tool that projects corresponding to the thread-groove configuration on a section normal to the axis of the screw-shaped portion to be machined is prepared. The axis of the tool is positioned in parallel with the axis of the screw-shaped portion to be machined, and the relevent surface of the screw-shaped portion is machined by moving the tool relative to the screw-shaped portion while their axes are being kept in parallel with each other. According to the present invention, the lead of a small-diameter, deep-grooved female screw-shaped portion may be able to be machined. In addition, an ordinary NC machine tool can be used to machine leads of screw-shaped portions simply by making changes in the NC program.

Abstract: There is a method of making a threaded hole in a workpiece 15 whereby a core hole 9 is produced in the workpiece 15 with a combination drilling and thread milling tool 14 being advanced axially and threads are generated in the wall of the hole by a helical motion of the combination tool 14. It is desirable that the combination tool should be capable of making core holes whose diameter is greater than the drilling edge outer diameter of the combination tool. This is achieved in that the combination drilling and thread milling tool 14 in making the core hole 19 is moved on a helical path 11, 12 relative to the workpiece 15. Depending on the setting of the radius of the helical path, a different size inner diameter of the core hole is obtained.

Abstract: For machining male or female screws, especially of considerably large size diameter, variable pitch or taper, as desired, a machining center is used which is composed of a work table mounting the work fixedly thereon, and a rotatable machining spindle exchangeably fitted with a thread-cutting tool. Axial feed and rotational speed of the spindle are driven by respective drive motors. In addition, the work table is fed bilaterally on a plane perpendicular to the axis of the spindle by respective feed motors. All these four motors are controlled synchronously by respective controllers which are subjected to control by a single parent numerical controller.

Abstract: When round screw thread machining is performed with a tool (TL) having a radius smaller than a circular arc radius of a threaded portion (RST), data necessary for deciding (i) tool path patterns of round screw threading cycles (PLi) and (ii) a starting point (Pi) of each round screw threading cycle are commanded and incorporated in NC command data of the round screw threading cycles, the cycle starting point (Pi) of each round screw threading cycle (PLi) is obtained along the circular arc profile of the round screw thread using the data, and round screw thread machining is performed by repeatedly executing the threading cycles while successively shifting the cycle starting point.

Abstract: The present invention relates to a speed reduction apparatus for globoid worm gears. The speed reduction ratio of the engaged worm globoid worm gear and worm wheel is defined as the ratio of the rate of rotation of the globoid worm gear about its axis to the rate of rotation of the worm wheel about its axis. The structure of the present invention speed reduction apparatus is defined by the distance between the axes of rotation of the worm wheel and globoid worm gear and the spacial and speed relationships between the globoid worm gear and the surfaces of the cutting tool employed to generate the worm gear.

Abstract: A milling process to produce profiles on rod-like workpieces at a high rate of cutting. The profiles are produced in cutting segments.An apparatus is provided wherein the cutting edges are mounted on a milling head. The milling head rotates about its own axis and performs a relative circulating movement about the axis of the workpiece as well as a relative linear feed movement. The rotational and circulating movements are coordinated with one another in such a way that in accordance with their different radial positions and different cutting edge shapes the individual cutting edges form the profile on segmental portions of the contour while successively moving into the profile plane of the workpiece.

Abstract: Method for producing threads and machine tool for thread milling, wherein in order to avoid high cutting speeds and also to produce short millings, a milling cutter is used, which comprises several teeth forming at least one thread, rotates at the point of engagement in the opposite direction to the workpiece, encompasses the latter during the production of an external thread with substantial radial play or in the production of an internal thread is encompassed by the workpiece with substantial radial play, and wherein the advance s of the milling cutter meets the following condition:s=h.multidot.(1-i)with h representing the pitch of the thread to be produced and i the rotational speed ratio of milling cutter and workpiece differing from 1.

Abstract: A method and apparatus are disclosed for machining hourglass screw threads on an enveloping-type worm screw by engaging at least one angularly positioned cutter with a screw blank having an hourglass shape. The screw blank is rotated about its central longitudinal axis at the same time that each angularly positioned cutter is pivoted through the screw blank at a rate which is less than the rate of rotation of the screw blank.

Abstract: Thread rolling dies for pointed fasteners having an improved working face contour which promotes displacement of blank material from the blank point area at an early stage in the thread rolling sequence to avoid excessive pressures in the die and blank at the finishing stages of the rolling sequence. Thread cutters include an extended section that presurfaces the rise angle of the die working face to produce uniform, improved thread profiles.

Abstract: A method for shanking a rock bit utilizing a shank locator and a cone locator, each with tapered surfaces to engage respectively the tail stock of a lathe and the cones of a rock bit, to accurately align the body and the cones of the bit concentric with the design centerline of the bit. The lathe and cone locators each have interior conical surfaces to assure accurate, coaxial alignment of the shank end and the cone end of the bit. A compensating chuck is used to grip the cone end of the bit body and firmly hold the normally uneven surfaces while the threads are being machined.

Abstract: A self-sharpening refractory metal cutting tool presenting an overhanging cutting portion, i.e. a flange, or ledge, of width equal to (or slightly greater than) the depth of the cut to be taken and maximum thickness equal to tolerable tool flank wear is disclosed. This tool construction has special utility in a novel high-speed cutting method in which only the tool flange does the cutting in which operation the flange is worn away with the wear progressing lengthwise of the flange during which time the flange sequentially performs a roughing cut and then a finishing cut in a single pass.

Abstract: A process for dressing a single or multiple-grooved worm or threaded workpiece by a single or multiple-grooved worm or threaded dressing tool includes the turning of the workpiece and tool with the dressing tool in a comb-type contact with the workpiece. By using an additional axial relative movement between the dressing tool and the workpiece, determined by the radial positioning and return movements, the contact points are displaced such that the desired grinding profile is produced on the workpiece. Since the entire surface area of the instantaneous contact points is significantly smaller than the entire profile area of the workpiece, the cutting forces which occur are relatively small, so that high dressing speeds can be obtained. It is also possible to make various flank corrections on the workpiece. The apparatus for carrying out the process is also disclosed.

Abstract: A cutting insert includes a planar body member formed unitary with peripheral ledges of smaller width than the body member, with the ledges being configured and aligned relative to the body member to achieve desired rake angles, both axial and radial as well as the clearance angle desired of the cutting geometry. In operation, each elongated ledge defines the cutting edge of the cutting insert and during operation of the cutting insert, the ledge is consumed and thus generates a fresh edge behind it along the entire length of the ledge such that the cutting process may be maintained continuous until the entire length of the ledge is consumed. The cutting insert may then be indexed to the next ledge cutting edge.

Abstract: Continuous machining of grooves in a cylindrical dielectric rod is achieved by guiding the rod into a heating machining head incorporating a rotating cutter made from a chemically etched stainless steel sheet and guiding the rod downstream of said head. A chip removing head made of a rotating unit comprising channels in which said chips are aspired by decompression effect of a gas is mechanically coupled with and upstream of the machining head.