Abstract: The invention relates to an axial thread rolling head, comprising a head part, in which at least three thread rolls are rotatably mounted, wherein the thread rolls among themselves border an insertion section for a workpiece and wherein the thread rolls each have a profile for forming an outer thread on the workpiece, wherein the thread rolls are held non-adjustably in the radial direction in the head part, wherein the profile of the thread rolls is respectively designed asymmetrically such that the thread rolls with their asymmetrical profile form a symmetrical external thread on the workpiece. The invention also relates to a corresponding method.

Abstract: A novel structure of an active electro-optical device is disclosed. The device is provided with complementary thin film insulated gate field effect transistors (TFTs) therein which comprise a P-TFT and an N-TFT. P-TFT and N-TFT are connected to a common signal line by the gate electrodes thereof, while the source (or drain) electrodes thereof are connected to a common signal line as a well as to one of the picture element electrodes. In case of driving the active electro-optical device, a gradation display can be carried out in a driving method having a display timing determined in relation to a time F for writing one screen and a time (t) for writing in one picture element, by applying a reference signal in a cycle of the time (t), to the signal line used for a certain picture element driving selection, and by applying the select signal to the other signal line at a certain timing within the time (t), and whereby setting the value of the voltage to be applied to a liquid crystal.

Abstract: A device for drilling an undercut in a borehole formed into a substrate includes a housing (1) containing a guide sleeve (2) with a bushing (4) arranged eccentrically within and rotatable relative to the guide sleeve. A torsion spring (6) is located between the guide sleeve and the bushing and is stressed when the bushing rotates relative to the sleeve. A drive shaft (8) with a cutter head (9) at one end is supported in the bushing and can be moved from a centered position into an eccentric position relative to the guide sleeve for forming the undercut. The rotational drive of the bushing (4) is afforded by the drive shaft (8) via an eccentric gear train. Furthermore, the gear train includes an internal ring gear (23) couplable to a gear train housing (19) by a wrap-around spring (31).

Abstract: A device, for cutting an undercut in a borehole at a location spaced from the surface of a material into which the borehole is formed, includes a housing (1) with a bore therethrough and a guide sleeve (2) rotatably supported in the housing bore and having an eccentric bore therein. A bushing (3) with an eccentric bore is rotatably supported in the guide sleeve bore. A drive shaft (7) is rotatably supported in and extends through the eccentric bore of the housing and has a cutter head (9) at one end. The drive shaft (7) can be shifted from a centered position within the housing bore into an eccentric position by rotation of the bushing (3) relative to the guide sleeve (2). In the eccentric position, the cutter head (9) can penetrate into and form an undercut in the surface of the borehole. A displacable snap-in element (16) in the housing (1) prevents rotation of the guide sleeve (2).

Abstract: A device for drilling an undercut (1b) in a borehole (1a) in a target material 1, includes an axially extending guide sleeve (13) containing an axially extending eccentric bore, an eccentric bushing (14) is supported rotatably in the guide sleeve and a drive shaft (15) is supported rotatably in the eccentric bushing. A housing (10, 12) laterally encloses the guide sleeve and bears against the surface of the target material. A blocking member (25) is positioned between the housing (10, 12) and the guide sleeve (13) for permitting rotation of the guide sleeve in only one rotational direction relative to the housing (10, 12). Due to the blocking member (25) entrainment of the guide sleeve (13) is prevented when the eccentric bushing is rotated in the direction opposite to the one rotational direction.

Abstract: A blade clamping device for securing a blade assembly on a rotary cutting tool having a body formed with a cylindrical surface concentric with the axis of the cutting tool. The clamping device selectively locks the blade assembly in position along a radially disposed track which is defined by an elongated slot extending radially from the cutting tool body's outer diameter to its inner bore and a key-shaped channel formed inwardly of the elongated slot's bottom wall. A ball head screw is slidingly retained in the key-shaped channel such that its threaded shank is held in threaded engagement with a threaded aperture formed in the blade assembly in order to provide a means to selectively clamp the blade assembly in position along the elongated slot.

Abstract: Coarse radially adjustable tool holder employing eccentric adjustment ring combined with linear guide means confining tool point to linear adjustment path within fine adjustment eccentric bushing such as provided by "Briney Precision Adjustment Tool".

Abstract: The invention relates to rotary cutting tools (10) provided with cutting means and mounted in a tool holder (11). A sleeve (17) provided with an eccentric bore is rotatably positioned between the tool holder (11) and the cutting tool (10) for radial adjustment of the cutting means. For purposes of making possible use of cutting tools having center cutting means the sleeve (17) is rotatable relative to the tool holder (11) about an axis (18) which is radially spaced from the rotational axis (21) of the cutting tool (10).

Abstract: A revolving drill head or the like with finely adjustable tool carriers at right angles to its longitudinal axis having high rigidity material-elastic intermediate members operable by a hydraulic pressure medium supplied coaxially to the shaft of the drill head in a feed mechanism, which is positioned in fixed manner between the shaft and the tool carrier and having two flange-like connecting parts to the shaft or tool carrier connected by two axially parallel, resilient parts at right angles to the shaft axis as a parallel guide and with counter-directed, diametrically facing shaft axis parallel extensions which are symmetrical to and spaced from the shaft axis and between which is provided an expansion member as a material-elastic intermediate member in a plane at right angles to the shaft axis, each of the flange-like connecting parts has a compensating device diametrically facing with respect to the shaft axis the extension fixed thereto for compensating its unbalance in at least one relative position of

Abstract: A router bit having an adjustable blade for cutting various widths of grooves includes a mechanism for maintaining static balance about the axis of rotation for all positions of the cutting blade within the range of adjustment. The router bit includes a main body adapted to be held and rotated by a chuck, and which includes a bore whose axis is parallel to but displaced from the axis of rotation of the main body. An arbor with an offset cutting blade is adjustably mounted in the bore, and the width of the groove is determined by the angular position of the arbor within the bore. However, such adjustment alters the static balance of the router bit about its axis of rotation. In accordance with the present invention, this source of unbalance is compensated by providing a counterweight whose position is dependent on the angular position of the arbor within the bore. In the preferred embodiment a cam on the shaft of the arbor bears against and determines the position of the counterweight.

Abstract: A precisely adjustable cutting tool holder for a machine tool employs an eccentric shaft to directly engage and thereby to pivot a tool holding part with respect to a stationary part that is secured to the machine tool. Threaded members that engage another eccentrically oriented member may be used to minimize backlash between moving parts of the mechanism.

Abstract: The invention pertains to a fine adjustment for the tool of a machine tool. The tool carrier is displaceable by forces generated by the rotation of a shaft through an eccentric wherein the shaft is indexed by a reversible electric stepping motor. Tool adjustments of thousandths of an inch are accurately and consistently achievable.

Abstract: A dual spindle assembly is provided which has a hollow outer member having an inner member rotatably and eccentrically mounted therein. The inner spindle member has a mounting hole defined eccentrically in one end for engaging a cutting tool. In order to make possible a continuous change in the radius of revolution of the cutting tool about the axis of the outer spindle member, a plurality of worms extend parallel to the spindle assembly and are geared to one another for joint rotation. Ball nuts on the worms travel back and forth along the same with the bidirectional rotation thereof. Rigidly interconnecting the ball nuts, a connector surrounds the spindle assembly via a ring rotatably mounted therein. The ring has an inward projection making threaded engagement with the inner spindle member through a slot cut longitudinally in the outer spindle member. The linear travel of the ring with the ball nuts results in the rotation of the inner spindle member relative to the outer.

Abstract: A holder for a tangential chasing tool is supported in a tiltable manner in a thread cutter head which opens automatically. The holder has a chaser seat as well as a clamping plate including a guide claw. The clamping plate secures the dovetail portion of the chaser tool with the aid of a clamping jaw and two clamping screws. Exchangeable intermediate disks having different wedging angles, are insertable into the chaser seat. The bottom edge of said guide claw of the clamping plate has a convex shape, whereby the chaser tool is securely held in the holder without the need for a plurality of chaser holder sets and without any substantial modification of the holder structure.

Abstract: A holder for use with a screw cutting diehead of a machine tool, the holder having a recess for the reception of a thread chaser element, which recess has a surface arranged to locate the chaser element therein at a predetermined helix angle, and the holder being adapted to permit the element to be gripped in position therein. The invention also includes the combination of a chaser carrier and separate chaser holder mounted therein.

Abstract: A cutting tool holder for supporting a cutting bar is provided in which the radial distance between the axis of the cutting tool holder and the cutting edge of the cutting bar is adjustable. The cutting tool holder comprises a hub member having a tubular bushing rotatably mounted in an axial bore at the outwardly extending axial end of the hub member. The inner bore of the bushing is eccentric with respect to the axis of the hub member. The cutting bar is secured to a bar holder having a shank which is received in the eccentric bore. A circular drive plate is fastened across the inner end of the bar holder and prohibits both axial and rotational movement, but permits a radial movement of the bar holder within the eccentric bore. A first tubular and cylindrical bearing sleeve, constructed of a compressible material, is disposed between the bushing and the hub member.

Abstract: There is disclosed a self-retracting tool holder assembly for mounting a tool on a machine in a predetermined location with respect to a workpiece, the assembly incorporating a tool holder mounted for pivotal movement about an axis so arranged that when the tool is fed by the machine into engagement with the workpiece the forces created by such engagement will cause the tool holder to pivot about said axis to advance the tool into a seated machining position in which the machining portion of the tool is displaced into the workpiece both in the feed direction and in a direction at right angles thereto, and spring means to automatically retract the tool to an inactive position out of engagement with the workpiece when the feed of the tool stops, whereby when the tool is returned by the machine the tool will not cause a drag line to be formed on the just-machined surface of the workpiece.