Abstract: A rotary tool holder (1) with a balance device, having a cylindrical body (5) containing a T-section circumferential slot (7) and balance weights (8) in the shape of circular sectors attached with a snap action to the circumferential slot (7), the weights (8) being moveable and angularly positionable relative to the body (5) of the tool holder (1).

Abstract: A spindle supporting box structure, wherein longitudinal parts forming both ends of lateral parts at each of right and left longitudinal side faces facing, with a spindle therebetween, in a direction almost perpendicular to longitudinal side faces facing in a front-back direction are formed by longitudinal tubular members having suitable flexural rigidity. A damping structure wherein required frameworks of structures are formed by tubular members and wherein concrete is filled in the tubular members and then solidified. As an alternative, a powdery damping material or a jelly damping material is airtightly sealed in the tubular members. An inner space of one or more of the tubular members is made into a gas pressurized tank wherein a balance cylinder is connected to the gas pressurized tank and wherein the gas in the gas pressurized tank directly acts on a cylinder chamber of the balance cylinder.

Abstract: A tool holder for use in a rotating spindle of a milling machine. The tool holder comprises a conically tapered shank portion for insertion into the spindle and a cutting tool mounting portion. Disposed between the shank and mounting portions is a flange portion. Additionally, extending about the shank portion is a dampening member. The dampening member is compressible between the flange portion and the spindle when the tool holder is inserted into the spindle, and is adapted to eliminate harmonic resonance attributable to the use of the tool holder with an extended shank cutting tool.

Abstract: Methods of and apparatuses for mitigating chatter vibrations in machine tools or components thereof. Chatter therein is suppressed by periodically or continuously varying the stiffness of the cutting tool (or some component of the cutting tool), and hence the resonant frequency of the cutting tool (or some component thereof). The varying of resonant frequency of the cutting tool can be accomplished by modulating the stiffness of the cutting tool, the cutting tool holder, or any other component of the support for the cutting tool. By periodically altering the impedance of the cutting tool assembly, chatter is mitigated. In one embodiment, a cyclic electric (or magnetic) field is applied to the spindle quill which contains an electro-rheological (or magneto-rheological) fluid. The variable yield stress in the fluid affects the coupling of the spindle to the machine tool structure, changing the natural frequency of oscillation.

Abstract: An ophthalmic lens generating apparatus having a tool spindle comprising a motor, a lens surfacing tool and a coupling mounted between the motor and the lens surfacing tool for retaining the lens surfacing tool to the arbor of the motor. The apparatus of the present invention also comprises a first actuated table supporting the tool spindle in a movable manner along the longitudinal axis of the apparatus. A massive base is mounted beneath the first actuated table for supporting the table and for dampening radial vibrations of the tool spindle. The apparatus further comprises a lens holder for holding an ophthalmic lens in a plane substantially perpendicular to the longitudinal axis of the apparatus. A massive upright block is mounted on one end of the massive base behind the structural support supporting the lens holder, for dampening axial vibrations of the tool spindle and of the lens holder.

Abstract: The present invention provides vibration damping method and apparatus that can damp vibration in more than one direction without requiring disassembly, that can accommodate varying tool dimensions without requiring re-tuning, and that does not interfere with tool tip operations and cooling. The present invention provides active dampening by generating bending moments internal to a structure such as a boring bar to dampen vibration thereof.

Abstract: In the tool body (2), a tool support (4) for a cutting-plate holder (6) is mounted capable of fine radial movements. To compensate for imbalance, a balancing device (30) is provided which has at least two weight bodies (20, 21) movable in opposite circumferential directions within the tool body (2) in essentially the same plane. In certain embodiments, each of the two weight bodies (20, 21) forms approximately one-fourth of a circular ring.

Abstract: A method that eliminates or reduces chatter when plunge cutting with boring cutters at different diameters, different tool geometries, different chip loads and different cutting depths, by computing optimal cutting insert locations and relocating such inserts to such optimal cutting locations with different phase angles therebetween; this minimizes the resultant radial force of the combined cutters.

Abstract: A lead slug is axially slidably mounted within a longitudinal cavity in the oring shaft of an automatically tuneable anti-vibration boring system. The lead slug is resiliently held in the longitudinal cavity by resilient spring members at its axial ends thereby permitting resonant axial vibration at a frequency determined by the mass of the lead slug and the spring constant of the resilient spring members. A vibration detector within the boring shaft transmits a vibration signal to a controller in response to a vibration of the boring system. The controller transmits a signal to a linear actuator which changes a preload on the resilient spring members, and thereby changes the resonant axial vibration frequency of the lead slug. The linear actuator moves toward or away from the lead slug until the lead slug, resonating at its resonant frequency, reduces the vibration of the boring system.

Abstract: A rotary tool, in particular a high-speed milling or boring tool, has at least two balancing rings (17, 18) with a variable mass around their circumference mounted on the tool holder or tool body (1). Two concentric balancing rings (17, 18) whose position in relation to the axis of rotation (6) of the tool (1) may be adjusted are releasable mounted in the tool holder or in the tool body (1) and are supported in the radial direction (14) in the tool holder or tool body (1). A short rotary tool (1) is thus obtained with a simple support of the balancing rings (17, 18) in the radial direction.

Abstract: Disclosed is a tunable damping system for use in reducing vibrations associated with metal cutting and tooling. The tunable damping system may be located in a boring bar, an end mill, a modular tool section or the spindle/tool holder of the metal cutting machine. The tunable damping system incorporates a damper mass, elastomeric supports, and a means to lock the mass so as to determine tuning parameters. A tuner assembly consists of sensors and a microprocessor capable of recognizing the most dynamically flexible mode of vibration. The tuner assembly is also capable, through signal processing and microprocessor controlled algorithms, to direct the operator in implementing the proper tuning adjustments of the tunable damping system.

Abstract: Boring bar vibration damping is improved by a novel use of the electromechanical properties of the piezoelectric actuator material. A negative capacitance shunt circuit is provided in which a voltage-controlled voltage-source continuously simulates a negative capacitance that is substantially equal in magnitude but opposite in phase to the capacitance of the piezoelectric material. The negative capacitance is shunted across the piezoelectric device, effectively compensating for the capacitance of the device across a broad frequency band. The voltages generated in the piezoelectric element in response to mechanical deformation induced by broadband vibrations of the structure during damping operations, may then be completely resistively dissipated, thereby enhancing the mechanical damping.

Abstract: An apparatus for balancing the grinding wheel (2) of a grinding machine, comprising an assembly coupled to and rotating with the wheel and including masses (24, 26) the position of which is adjustable and electrical motors (28, 30) to control adjusting movements of the masses. The electrical connection between the motors and a survey and processing unit (16) including a power source (40) is provided by slip rings (48) and brushes (54). The brushes are fixed to a movable support (52). A spring (58) acts on the movable support to space the brushes apart from the slip rings. An actuator including, for example, electromagnets (60) acts on the movable support to perform the contact between the brushes and the corresponding slip rings.

Abstract: Disclosed is a tunable damping system for use in reducing vibrations associated with metal cutting and tooling. The tunable damping system may be located in a boring bar, an end mill, a modular tool section or the spindle/tool holder of the metal cutting machine. The tunable damping system incorporates a damper mass, elastomeric supports, and a means to lock the mass so as to determine tuning parameters. A tuner assembly consists of sensors and a microprocessor capable of recognizing the most dynamically flexible mode of vibration. The tuner assembly is also capable, through signal processing and microprocessor controlled algorithms, to direct the operator in implementing the proper tuning adjustments of the tunable damping system.

Abstract: A device is provided to eliminate unbalance and vibration occurring due to nonsymmetrical mounting of rotatable tools and tool holders in milling machines, arboring machines, drilling machines, etc. Attached to the tool holder in an appropriate place is a weight support able to receive one or more appropriately sized weights. The weights being radially adjustably securable to the weight support.

Abstract: An apparatus and method for balancing a high speed rotary tool assembly (1) is provided, wherein the apparatus includes a rotary tool holder (3) having an axis of rotation (11), a cutting tool retainer (13) in the rotary tool holder (3) having a lockring (23) that circumscribes the axis of rotation (11) of the holder (3), and a pair of axially spaced balancing rings (35a, 35b) for balancing the entire rotary tool assembly (1) which are rotatably mounted around bearing surfaces (37) circumscribing the lockring (23) so as to be angularly positionable around the axis of rotation (11) of the tool holder (3). In the method of the invention, the unbalance of the tool holder (3) and cutting tool (17) is first determined, and then the rings (35a, 35b) are rotatably adjusted about the bearing surface (11) on the lockring (23) to create an unbalance which cancels out the determined unbalance of the tool holder (3) and cutting tool.

Abstract: A linear motor control system and method to increase apparent motor stiffness by providing linear motor resistance to perturbations caused by external forces exerted on a slide mass and a base mass. Primary and secondary sensors detect the accelerations of the slide mass and the base mass relative to ground and generate acceleration signals corresponding thereto. A position detector senses the position of the slide mass relative to the base mass and generates a position signal corresponding thereto. A signal processor processes the first and second acceleration signals and the position signal to determine deviations in the position, velocity and acceleration of the slide mass relative to the base mass from selected values caused by the external forces, and to generate a motor control signal to provide linear motor resistance against such deviations.

Abstract: A method and apparatus for balancing tools 16 is disclosed which may uniquely characterize a needed balance for each of the individual tools 16 and which may then store the needed balance conditions so as to use the balancing data upon every use of the individual tool 16. This balance is achieved, in one embodiment, by the movement of certain balancing objects 28 from a balance containment member 22 to cavities 26 within a balance reception member 24. Should the original balance condition falter, the apparatus and methodology of this invention allow the balance conditions to be updated, dynamically, and to be stored for later use.

Abstract: An active vibration control device for controlling vibration in a cantilevered member and a method for the same are disclosed. The device is comprised of a cantilevered member having a longitudinal axis comprising a sensor mounted near the free end of the member to measure motion of the member in a transverse direction and to produce a corresponding signal. A force generating assembly is mounted to the member near the free end to oppose the measured motion with a force thereby minimizing subsequent motion along the transverse axis caused by vibration.

Abstract: Disclosed is a balancer attachment for the spindle of a machining apparatus using two primary and secondary balancers operatively coupled so as to allow the primary balancers to take major part in balancing while an associated tool traverses a short distance, and allow the secondary balancers to take major part in balancing while the tool traverses a long distance. These balancers follow circular arcs to bring their weights in the direction which is opposite to the linear displacement of a tool-carrying slide, thereby maintaining equilibrium in the rotating mass.

Abstract: A vibrating cutting tool having an input shaft driven by a live spindle of a machine tool and an output shaft having a cutter mounting portion. The input shaft and the output shaft are coupled together through a coupling mechanism so as to be at least circumferentially movable relative to each other. Recesses are formed in one of the input shaft and the output shaft and holes are formed in the other at locations opposite to the recesses. Moving elements are mounted between the recesses and the holes with a predetermined gap defined between the moving elements and the recesses or the peripheral surfaces of the holes. The gaps serve to restrict a circumferential movement of the moving elements. Springs are provided to urge the moving elements against the recesses. The movement of the moving elements is restricted by stoppers. An adjusting ring may be provided to adjust the biasing force of the springs.

Abstract: The invention is directed to a brake lathe having a device to eliminate or reduce vibration. Various types of dampers may be mounted on the arbor shaft of the lathe.

Abstract: The present invention entails a method and apparatus for balancing a high speed rotary tool assembly. A pair of closed balancing rings are journalled about a cylindrical bearing surface formed around a rotary tool holder with each ring being rotatively mounted about the bearing surface independently of each other. The tool holder is adapted to receive and hold a cutting tool. After determining the unbalance of the tool holder and cutting tool, the rings are rotatively adjusted about the bearing surface to create an unbalance within the tool rings and the position of the tool rings is adjusted such that the created unbalance of the tool rings is disposed opposite the determined unbalance of the rotary tool holder and cutting tool.

Abstract: A multi-faceted T-slot cylinder for a cutterhead is mounted to a wood lathe arbor using set screws installed in tapped holes which are provided near opposite ends of the cylinder in diametrically opposite faces of the cylinder (rather than in the same face, as is conventional). Static balancing of the cylinder is thereby improved. For fine-tuning, a dynamic balancing collar is mounted on the arbor near the cylinder. This collar has a plurality of tapped holes provided radially therethrough around its circumference. As the arbor is turned slowly, if measurement shows eccentricity in rotation, the high side is determined and a set screw tightened against the arbor in the respective tapped hole. This dynamic balancing can be done before or after the cutterhead is installed on the arbor, and the dynamic balancer can be used in combination with a wholly conventional T-slot cylinder.

Abstract: An apparatus for peeling a layer from a surface, including a nonplanar surface such as the hull of a ship, comprises a rotatable substantially cylindrical support with at least two peeling knives projecting from an outer surface thereof. An annular guiding element surrounds each end of the substantially cylindrical support, and these annular guiding elements have different diameters. Preferably, the peeling knives are spaced unequally around the circumference of the substantially cylindrical support.

Abstract: A multi-faceted T-slot cylinder for a cutterhead is mounted to a wood lathe arbor using set screws installed in tapped holes which are provided near opposite ends of the cylinder in diametrically opposite faces of the cylinder (rather than in the same face, as is conventional). Static balancing of the cylinder is thereby improved. For fine-tuning, a dynamic balancing collar is mounted on the arbor near the cylinder. This collar has a plurality of tapped holes provided radially therethrough around its circumference. As the arbor is turned slowly, if measurement shows eccentricity in rotation, the high side is determined and a set screw tightened against the arbor in the respective tapped hole. This dynamic balancing can be done before or after the cutterhead is installed on the arbor, and the dynamic balancer can be used in combination with a wholly conventional T-slot cylinder.

Abstract: An improved high-speed spindle assembly for a shank-driven cutting tool comprises a hollow spindle for a collet, a titanium alloy drawbar within the spindle for threadingly engaging the collet, and a tubular resilient member within the spindle surrounding the drawbar for damping vibrations. A transverse resilient member in a threaded portion of the collet resists rotation of the collet on the drawbar. A ten-tooth involute spline provides precise sliding engagement of the drawbar within the spindle. A pair of ball bearings are axially clamped to the spindle by a pair of titanium nuts, a lower nut having a flange closely spaced from an external annular surface of a spindle housing for excluding foreign matter, an upper nut having a cavity for axially retaining a flange of the drawbar.

Abstract: The arrangement enables controlling the speed of advance of the tool part of a machine tool during its approach phase toward a workpiece and reducing such speed as soon as the tool contacts the workpiece.It includes an acoustic sensor adapted to detect the signal emitted at the instant of contact, an electronic circuit for processing such signal and a motor responding to the circuit to regulate the speed of advance of the tool part. The sensor is fastened to a feeler mounted on the machine framework by means of shock absorbers, said feeler being arranged to be in contact with the workpiece or its carrier.

Abstract: A rock cutting assembly consists of a rock cutting roller, a shaft on which it is mounted, and a means for varying the mass of the assembly about the drive axis, to vary the balance of the assembly about that axis. Preferably two rollers are mounted on a common drive axis, the axes of the rollers being diametrally opposed and eccentrically displaced by the same distance from the drive axis. The mass-varying means may be a cavity or cavities in the hub or hubs, with means to introduce fluid into and extract it from the cavity or cavities. Alternatively the means may be a weight mounted to permit adjustment to vary the degree of imbalance.

Abstract: In an engraving head for apparatus for engraving printing cylinders, a drivable engraving tool and a sensing organ contacting any printing cylinder being engraved by the drivable engraving tool are mounted on a common fixture. A damping element is located between the sensing organ and the engraving tool for at least substantially barring transmission of oscillations from the sensing organ to the engraving stylus, while preserving a firm and accurate guidance of the drivable engraving tool by the sensing organ contacting the printing cylinder. Damped sleeve structures and collets for mounting a sensing stylus include such damping elements.

Abstract: A vibration absorption apparatus for a reciprocating object, in which the reciprocating object is reciprocated along a pair of parallel tracks and a vibration absorption member is moved in the direction opposite to the movement of said reciprocating object.

Abstract: A balancing chuck is disclosed for semiconductor wafers having a flat region which typically causes wafer imbalance on spinning equipment. The wafer's flat region is determined by a proximity sensor mounted on a centering arm overlying the wafer. The chuck is constructed to include an annular race containing a spherical counterweight. As the chuck is rotated to determine the wafer's flat region, a magnet prevents movement of the spherical counterweight within the race and allows for its subsequent alignment with the mass imbalance. A plurality of circumferential pockets are provided within the race to retain the position of the counterweight which functions as a counterbalance maintained in proper angular alignment during spinning of the chuck.

Abstract: A boring tool with interchangeable tool bit holders is equipped with weight balancing members pivotable about a common fulcrum located on the rotation axis of the fine boring head. The weight balancing members are in the form of circular segments. They are pivoted from their given position about the common fulcrum by means of pull cords fixed thereto. In principle, each pull cord is fixed to each weight balancing member. Thus, a first pull cord fixed to one side of two weight balancing members is guided about a first guide bolt and a second pull cord fixed to the other side of the two weight balancing members is guided about a second guide bolt.

Abstract: A damped boring bar assembly for damping the vibrations encountered during the high-speed boring of titanium, zirconium, and their alloys and the like, as well as steel and other metals, especially when the overhang, or ratio of the diameter to depth of the bored hole, is very small. The boring bar assembly has a weighted damper body contained within a hollow elongated case, the tool-holding end of which is closed and incorporates a shaped inner face with a frictional sliding surface. The damper body also has a frictionally slidable element which, with the damper body, holds a resilient element in compression in an internal cavity. The frictionally slidable element has a shaped face having a frictional surface thereon which engages the frictional surface of the inner face of the elongated case during vibration. The damping mechanism can be adjusted to handle different machining conditions.

Abstract: A roller hold down device for removable work table which has a pair of rollers which extend transversely across the workpiece mounted on the movable table so as to hold it down and with a pair of cam roller members mounted on either side of the movable table and formed with cam portions so as to engage the rollers at the end of travel so as to force the rollers up away from the workpiece and also so as to prevent the rollers from falling off of the end of the workpiece. The rollers are controlled by hydraulic cylinders which can be actuated to automatically move them to the down position and also to move them to the up position.

Abstract: A cylindrical grinding process is controlled by measuring the precession of lobes about the grinding wheel and the workpiece and employing the measured lobe precessions to determine an exponential chatter growth index, which is a measure of the rate of growth of chatter and, accordingly, of the stability of the process. The wheel and workpiece rotational speeds are controlled to minimize the growth of chatter and to optimize the process.

Abstract: An elastomeric sleeve is fitted within a spindle bore over a coaxial spring assembly used to actuate a drawbar clamp. The sleeve takes up the radial clearance space normally provided for the spring assembly, so that as the diameter of the spring assembly changes during compression cycles, the sleeve will be radially compliant and tend to keep the spring assembly centered, thereby minimizing vibrations while the spindle is rotated.

Abstract: Disclosed is a boring tool resistant to vibration. There is a boring bar having a central bore at one end and a boring bar head for attachment to the boring bar at the one end. Inserted in the bore is a tuned absorber package for eliminating vibrations in the boring tool. The tuned absorber package is self-contained and is transferable between boring bars. Also disclosed is a method of reducing vibrations in the boring tool.

Abstract: A technique for reducing noise generated by transverse vibrations in elongated members comprises the application of a friction element on a surface of the member. The friction element is forced against one or more surfaces of the member by a selected normal force and is provided in a vicinity of maximum distortion of the member when the member undergoes vibrations. A differential movement between the inner surface of the friction element and the outer surface of the member causes heat to be generated which dissipates the energy of such transverse vibrations.

Abstract: A machine for machining sheets comprises an arrangement for compressing the sheets to be machined. The arrangement is rotatable about a longitudinal axis comprises at least two rollers for bearing resiliently against the sheets during machining, each of which rollers are rotatable about a transverse axis perpendicular to said longitudinal axis. The arrangement is driven by a motor via a pinion, which motor also drives reduction gearing connected to an angular control means whereby it is possible to control the angular position of the arrangement so that the axis of rotation of the rollers can be orientated in relation to the direction of machining. The control means are themselves controlled by programmable electronic means which operate with reference to the angular position of the machining head of the machine.

Abstract: The cutting force applied between the cutting tool and the workpiece of a machine tool is periodically pulsated to expedite removal of material from the workpiece. The periodic cutting force pulsation is produced by periodically varying the spindle speed or the feed rate or both. In one embodiment, the periodic speed variation is produced by universal joints in the spindle drive and worktable drive. In a second embodiment, the periodic speed variation is produced by elliptical gears in the spindle drive and worktable drive.

Abstract: A roller hold down is designed to restrain parts being cut from a stack of flat sheets. The roller hold down eliminates the need for secondary fastening means to restrain the parts during the cutting operation. The parts are restrained in position on a flat worktable by a pair of cylindrical rollers adjacent the cutter which force the parts against the table. By use of the roller hold down, the restraining force applied through the rollers follows the excursions of the cutter and is applied near the cutter where the force is the most effective.

Abstract: A feed system for machine tools in which rapidly changing cutting forces occur in milling machines with an hydraulic piston drive, a position control system and a carriage supporting either the tool or the workpiece for relative movement. The carriage is movably mounted on guides with preloadable bearings shiftably or swivelably. Dry-running friction bearings on the carriage are equipped with an automatically readjusting pressure arrangement, by means of which an adjustable shifting resistance is generated, which corresponds at least to the magnitude of the cutting force occurring. Preferably, the pressure arrangement consists of a pressure piston which may be acted upon by means of an adjustable pressure. In the case of the use of post guides, the bearings are equipped with three slide surfaces mutually displaced by 120.degree. and the pressure piston acts radially on one of the three slide surfaces.

Abstract: A machine spindle with a chuck at one end and a belt sheave at the other has torsional vibrations damped by an inertial wheel loosely received over the chuck.

Abstract: A roller hold down device for removable work table which has a pair of rollers which extend transversely across the workpiece mounted on the movable table so as to hold it down and with a pair of cam roller members mounted on either side of the movable table and formed with cam portions so as to engage the rollers at the end of travel so as to force the rollers up away from the workpiece and also so as to prevent the rollers from falling off of the end of the workpiece. The rollers are controlled by hydraulic cylinders which can be actuated to automatically move them to the down position and also to move them to the up position.