Abstract: An axial machining tool includes a cutter holder, a collet, a dust blower nut, and a cutter. The cutter holder has a receiving groove. The collet is extended into the receiving groove and has a containing space. The dust blower nut is sleeved on the collet and has a body, at least one blade, and a positioning element. The body has a threaded hole, a connecting groove, and at least one engaging groove. The threaded hole and the connecting groove are formed in the body and communicate with each other. The at least one engaging groove is formed on the body. The at least one blade is detachably mounted in the at least one engaging groove. The positioning element is mounted to the body and positions the at least one blade on the body. The cutter is extended into the containing space. A dust blower nut is also provided.

Abstract: A vibration assisted drilling system is presented. The vibration assisted drilling system comprises a drill feed motion system having a drill feed axis, an oscillation motion system having an oscillation axis, a drill spindle having a drill bit, and a mounting system configured to connect the drill spindle to the oscillation motion system. The drill feed axis is substantially parallel to and offset from the oscillation axis.

Abstract: Assemblies, apparatus, and methods are described for designing modulation tool holder assemblies and installations for modulation-assisted machining, and, in particular, for rotating machining applications that benefit from the sinusoidal modulation motion while cutting fluids are simultaneously applied through the tool. In addition, the design of rotating modulation tool holder assemblies and systems is described. In a tool holder assembly for modulation in a rotating spindle, the electric power and/or control signals are transferred from an external source to the modulation tool holder assembly installed in the rotating machine spindle. Similarly, the high-pressure cutting fluid is transferred from a stationary source to the rotating tool holder assembly for modulation.

Abstract: A tool (20) has a machine-side machine connection (21) for connecting the tool to a machine tool (1) for driving the tool in rotation (27) about a rotation axis (29) and for advancing (26) the tool relative to a workpiece, a workpiece-side tool head (22) having one or more cutting edges (25) for machining a workpiece, wherein the diameter (D) of the tool head is greater than 20 mm and wherein the cutting edges (25) of the tool (20) are arranged such that they travel over an area perpendicular to the rotation axis (29), a vibration unit (23) which is designed to set the tool head into rotary vibration (28) about the rotation axis (29), and a power receiving means (24) for wirelessly receiving supplied energy and for supplying electrical energy to the vibration unit (23).

Abstract: A tool unit applied to ultrasonic machining, includes an amplitude transformer, a machining head and a connecting portion. The machining head has a micron-sized array structure. With the connecting portion, the amplitude transformer and the machining head are assembled together and the connecting portion has a change in shape. The machining head includes a substrate and at least one diamond layer. An upper surface of substrate touches the amplitude transformer or the connecting portion. And the diamond layer is disposed on an lower surface of substrate. The material of the substrate is selected from a group of a steel material with thermal expansion coefficient ranged from 10.70×10?6K?1 to 17.30×10?6K?1, tungsten carbide and combination thereof. The material of the diamond layer is selected from a group of a diamond material with thermal expansion coefficient ranged from 1.00×10?6K?1 to 2.50×10?6K?1, a polycrystalline diamond, a diamond sintered body and combination thereof.

Abstract: Pipe machining apparatuses, tool supports, and methods of operating pipe machining apparatuses are provided. In one aspect, a pipe machining apparatus includes a frame, a tool carrier coupled to and movable relative to the frame, and a tool support coupled to and movable with the tool carrier relative to the frame. The tool support is adapted to support a tool and move the tool in a first direction toward a pipe at a first increment and move the tool in a second direction away from the pipe at a second increment. The second increment is larger than the first increment.

Abstract: The present invention relates to a tool holder device which comprises securing means (4) for securing a tool (24), a movable part (2) which can move in an axial direction and a pneumatic mechanism (3) which can cause an axial vibratory movement of the movable part (2). The securing means (4) are coupled to the movable part such that the axial vibratory movement of the movable part (2) is transmitted to the tool (24).

Abstract: A drilling head (1) with an axial oscillation generator, includes a mounting (2) for coupling the head to a motor for rotating the mounting about an axis, the mounting (2) having a longitudinal axis (5) coinciding with the axis of rotation of the motor, a tool holder (3), an elastically deformable element (6) for retaining the tool holder (3) in the mounting (2) and an element (7) for guiding the tool holder (3) in the mounting (2) along the longitudinal axis (5) of the mounting, wherein the mounting of the drilling head includes a controlled generator (8) of reciprocating movements in the direction of the aforementioned axis (5) positioned between the mounting (2) and the tool holder, the tool holder and the generator being connected by a longitudinal coupling member (9) suitable for damping the impacts withstood by the tool holder while enabling the transmission of the reciprocating movements.

Abstract: A machining method for at least one shaping machining operation can include carrying out a machining operation over a first distance using a cutting tool which is subjected to axial oscillations as it moves forward, then reducing the amplitude of the axial oscillations while continuing to drive the cutting tool in terms of rotation

Abstract: A device for use in a machining system, including an ultrasonic transducer, wherein the ultrasonic transducer is adapted to receive a tool bit; a housing adapted to be both compatible with the machining system and to receive the ultrasonic transducer, wherein the housing is operative to isolate all radial and other vibrations generated by the ultrasonic transducer except the axial vibrations transmitted to the tool bit; and a tool holder, wherein the tool holder and the top portion of the housing are mechanically coupled to one another.

Abstract: Assemblies, apparatus, and methods are described for designing modulation tool holder assemblies and installations for modulation-assisted machining, and, in particular, for rotating machining applications that benefit from the sinusoidal modulation motion while cutting fluids are simultaneously applied through the tool. In addition, the design of rotating modulation tool holder assemblies and systems is described. In a tool holder assembly for modulation in a rotating spindle, the electric power and/or control signals are transferred from an external source to the modulation tool holder assembly installed in the rotating machine spindle. Similarly, the high-pressure cutting fluid is transferred from a stationary source to the rotating tool holder assembly for modulation.

Abstract: A bore machine for producing a very precise bore, as well as a method of producing a very precise bore in a workpiece. The bore machine has a main drive that drives the spindle rotationally as well as travel along the axial direction and an auxiliary drive that provides an oscillating motion in the axial direction that is overlayed over the forward travel motion of the spindle. The auxiliary drive has a first element with a wave-shaped surface and that is movable relative to a second element. During relative motion between the first and second elements, one element is forced to follow the peaks and valleys of the wave-shaped surface, thereby generating the oscillating motion. The auxiliary drive is driven such, that the relative motion between the two elements is at most 30% of the rotational speed of the spindle.

Abstract: A rolling bearing includes at least a first ring with an undulating rolling surface and a second ring, the rings being coaxial and given a relative rotational and reciprocating axial movement, and at least one row of rolling bodies mounted in rolling contact between the respective rolling surfaces on the rings. The rolling bearing further includes at least a third ring with an undulating rolling surface that collaborates with either the first row of rolling bodies or with a second row of rolling bodies, the second row of rolling bodies being inserted between the rolling surface of the third ring and a rolling surface of a fourth ring. At least one of the third or fourth rings is mounted to rotate as one with the first or second ring respectively, and the rings which rotate as one are mounted such that they can move axially one relative to the other.

Abstract: The pneumatic drilling device includes: a ram provided inside a cylindrical body so that the ram can move forward and backward therein; a spindle air motor provided inside the ram; a feed air cylinder mechanism for moving the ram forward and backward; and an air supply port for supplying compressed air to the feed air cylinder mechanism and the spindle air motor through an airflow path. The airflow path includes: a first flow path for driving the spindle air motor; and a second flow path communicating with the feed air cylinder mechanism for moving the ram forward and backward. The first flow path and the second flow path are separately and independently provided in parallel.

Abstract: In this process for drilling a bore (61), a drilling tool (11) is driven simultaneously in rotation about an axis (A) and in translation along the axis (A) in accordance with an advance movement. The advance movement is combined with an oscillating movement of the drilling tool (11) along the axis (A) of an amplitude sufficient to break up the swarf formed, while at the same time keeping the drilling tool (11) in the bore (61) which is in the process of being drilled. In certain exemplary embodiments, the application may be relevant to the aircraft construction industry.

Abstract: The present invention concerns a tool head comprising a machine connection for connecting the tool head to a machine tool, and a tool 5 portion which either has at least one geometrically defined cutting edge or has a receiving means for a tool insert having a geometrically defined cutting edge. To provide a tool head, like a drilling head, and a method with which highly precise machining is possible with very high feed speeds and good surface quality without the cutting edge being exposed to 10 a high rate of wear, it is proposed that there is a converter for converting electrical AC voltage into a mechanical vibration, wherein the converter is arranged, designed and connected to the tool portion so that the unit comprising the converter and the tool portion and possibly a tool insert 15 received in the receiving means can be excited to perform an ultrasonic vibration.

Abstract: The invention concerns a perforating device comprising a cutting tool (10), means for rotating (11) the cutting tool (10) and means for translating (12, 14) the cutting tool (10), the ratio between the rotational speed and the translational speed being variable during rotation of the cutting tool (10). It comprises a gear train (16, 17; 18, 19) for synchronizing the rotating means (11) with the translating means (12, 14). The speed ratio between a driving pinion (16; 18) of the gear train, rotationally linked to the means (11) for rotating the cutting tool (10) and a transmission pinion (17; 19) of the translating means is reversed at least once during one rotation of the cutting tool (10). The invention is useful for fragmenting the resulting shavings.

Abstract: A control system for an air driven drill is described, wherein the control system is of the kind that provides a feed stroke to a drill bit. The system comprises an interrupt line so that compressed air fed to a feed chamber is also fed to a clamp chamber whereby the unbalanced force on the feed piston becomes balanced so as to stop the feed stroke. An adjustable frequency generator is provided to impose a pulsating pressure variation in an air pressure supply. During a feed stroke under which compressed air is fed to the feed chamber, air fed to the clamp chamber via the interrupt line is caused by the adjustable frequency generator to have a pulsating pressure, so that the feed stroke is caused to be stopped for a first period, then resumed for a second period, to provide a periodically interrupted feed stroke.

Abstract: A computer implemented method, apparatus, and computer usable program code for performing a drilling operation. The drilling apparatus comprises a housing, a spindle, a spindle motor, a thrust motor, a load sensor, and a controller. The spindle may be capable of receiving a drill bit. The spindle motor may be capable of turning the spindle at a set of different speeds during the drilling operation. The thrust motor may be capable of moving the spindle in an axial direction. The load sensor may be capable of detecting a reaction thrust force during the drilling operation to form a detected reaction thrust force. The controller may be capable of controlling the spindle motor and the thrust motor to change a drilling speed in response to changes in the detected reaction thrust force.

Abstract: A vibration suppressing device and a vibration suppressing method that are capable of obtaining an accurate optimum rotation speed and shortening a time period from generation of chatter vibration to calculation of the optimum rotation speed are provided. The vibration suppressing device includes: vibration sensors for detecting time-domain vibrational accelerations of a rotary shaft in rotation; and a control device for calculating a chatter frequency and a frequency-domain vibrational acceleration of the rotary shaft at the chatter frequency on the basis of the time-domain vibrational accelerations detected by the vibration sensors, and when the calculated frequency-domain vibrational acceleration exceeds a predetermined threshold value, calculating an optimum rotation speed on the basis of a predetermined parameter, and rotating the rotary shaft at the calculated optimum rotation speed.

Abstract: In the case of a method for chip-removing machining of workpieces (14), in particular for making bores in workpieces (14), wherein a tool (18) is put into rotation (20) relative to the workpiece (14) and the tool (18) is moved relative to the workpiece (14) with a feed motion, the tool (18) executes an oscillating motion in the direction (z) of the feed motion relative to the workpiece (14), a settable oscillation component being imparted to the feed motion through control means.

Abstract: A method of making a hole in a composite material comprising the steps of providing an elongate cutting tool having a cutting portion in the form of a tubular cylinder; and advancing the cutting tool in a direction parallel to a longitudinal axis of the cutting tool whilst rotating the cutting tool about said axis and vibrating the cutting tool along said axis.

Abstract: A drilling head (1) with an axial oscillation generator, includes a mounting (2) for coupling the head to a motor for rotating the mounting about an axis, the mounting (2) having a longitudinal axis (5) coinciding with the axis of rotation of the motor, a tool holder (3), an elastically deformable element (6) for retaining the tool holder (3) in the mounting (2) and an element (7) for guiding the tool holder (3) in the mounting (2) along the longitudinal axis (5) of the mounting, wherein the mounting of the drilling head includes a controlled generator (8) of reciprocating movements in the direction of the aforementioned axis (5) positioned between the mounting (2) and the tool holder, the tool holder and the generator being connected by a longitudinal coupling member (9) suitable for damping the impacts withstood by the tool holder while enabling the transmission of the reciprocating movements.

Abstract: A pneumatic feed drill has a control unit that repeatedly advances and retracts the drill bit in peck cycles while drilling the hole. The drill has a hydraulic damper cylinder with a damper rod protruding from it that limits the speed of advancement of the drill bit. A retainer device is mounted to the damper rod and prevents the damper rod from resetting to its initial position during the peck cycles. The retainer device releases the damper rod to reset when the drill bit has reached total depth. A safety device is pivotally mounted to the housing and has a closure tab that blocks access to the start button of the drill unless the damper rod is in its initial position.

Abstract: A machining system that includes an ultrasonic machining assembly, wherein the ultrasonic machining assembly further includes a machining tool; a collet adapted to receive the machining tool; and an ultrasonic transducer, wherein the ultrasonic transducer is operative to transmit acoustical vibrations to the machining tool; and a machining apparatus, wherein the machining apparatus is adapted to receive and secure the ultrasonic machining assembly, and wherein the machining apparatus is operative to transmit torque to the machining tool by applying rotary motion to the ultrasonic machining assembly.

Abstract: A device for use in a machining system, including an ultrasonic transducer, wherein the ultrasonic transducer is adapted to receive a tool bit; a housing adapted to be both compatible with the machining system and to receive the ultrasonic transducer, wherein the housing is operative to isolate all radial and other vibrations generated by the ultrasonic transducer except the axial vibrations transmitted to the tool bit; and a tool holder, wherein the tool holder and the top portion of the housing are mechanically coupled to one another.

Abstract: A drilling machine is provided for breaking chips formed by drilling action into manageable lengths. The drilling machine comprises a first gear having a first axis of rotation, and a cam follower surface. It has a second gear having a second axis of rotation coincident with the first axis of rotation. A housing is provided configured to support the first gear and the second gear, the housing having an undulating cam plate surface, a spring and a tool holder spindle having a third axis of rotation. The first and second gears are configured to impart both a linear feed and a rotation to the spindle. The first and second axes of rotation are coincident with the third axis of rotation such that the cam surface is urged into contact with the cam follower surface by the spring. The cam surface includes a plurality of steel balls positioned to follow the cam plate surface such that when the first gear rotates, the first gear is caused repeatedly to retract and then to advance, breaking chips that are formed.

Abstract: In order to effect drilling without any risk of blockage of the cutting tool used, a drilling device uses means for producing a self-maintained axial vibration of the tool that has the effect of breaking up the swarf of the material removed from the hole in order to facilitate discharge thereof. The means for producing the self-maintained axial vibration are also such that the spindle of the tool can have a direction substantially different from the rotation axis of the means used for rotating the tool. Such a device is particularly advantageous for producing deep holes or during the use of cutting tools producing asymmetric cutting forces. In a particularly advantageous embodiment, the means for producing the self-maintained axial vibration and for enabling the rotation axis of the tool to have a direction substantially different from the rotation axis of the drive means form part of the cutting tool.

Abstract: A small-diameter drill for deep hole drilling is provided which is capable of inhibiting the cutting chips from getting bitten and producing a straightness for a drilled hole, thus suitable for drilling a hole having a depth (L) which is 15 or more times the diameter (D) of a drilled hole. The small-diameter drill 1 has a diameter 2 which is 1 mm or less and a drill section 5 including cutting edge(s) 3 and flute(s) 4. The length 11 of the flute 4 is at least 5 times and at most 10 times the drill diameter 2. The diameter of the drill section 5, after being reduced in diameter from the cutting edge 3 toward the rear of the drill section 5, is expanded in diameter so that the outer diameter at the end of the flute 4 becomes at least 0.9 times and at most 0.98 times the drill diameter 2.

Abstract: A drilling machine is provided for breaking chips formed by drilling action into manageable lengths. The drilling machine comprises a first gear having a first axis of rotation, and a cam follower surface. It has a second gear having a second axis of rotation coincident with the first axis of rotation. A housing is provided configured to support the first gear and the second gear, the housing having a cam surface, a spring and a tool holder spindle having a third axis of rotation. The first and second gears are configured to impart both a linear feed and a rotation to the spindle. The first and second axes of rotation are coincident with the third axis of rotation such that the cam surface is urged into contact with the cam follower surface by the spring. The cam surface and the follower surface are shaped such that when the first gear rotates, the first gear is caused repeatedly to retract and then to advance, breaking chips that are formed.

Abstract: A drill has a tubular outer housing and a tubular inner housing. The inner housing is movable between extended and retracted positions. A pneumatic motor with a chuck mounts to the inner housing. Air pressure is delivered to annular pistons to cause the inner housing to extend and retract. Also, an annular hydraulic chamber with a variable orifice bypass controls the rate of feed. A processor records the total number of holes being drilled as well as recording the time duration for each hole.

Abstract: A method of controllably producing chips with a desired shape and size. The method generally entails machining a body with a cutting tool while superimposing modulation on the cutting tool so as to move the cutting tool relative to the body being machined and cause instantaneous and periodic separation between the cutting tool and the body at a point of contact between the cutting tool and the body, wherein each separation between the cutting tool and the body yields a chip. In this manner, the shapes and sizes of the chips are determined at least in part by the modulation cycle, and particularly the length of time the cutting tool is engaged with the body being machined.

Abstract: A method and apparatus for a power feed drill. The power feed drill comprises a servo motor, a roller screw, a ball spline shaft, an air motor, and a collet chuck. The roller screw is rotatably mounted to the servo motor. The ball spline shaft has a first end connected to the roller screw, wherein rotation of the roller screw in a first direction moves the ball spline shaft in the first direction and wherein rotation of the roller screw in a second direction moves the ball spline shaft in an opposite direction to the first direction along an axis. The air motor is capable of transmitting rotation motion to the ball spline shaft to rotate around the axis. The collet chuck is fixably attached to a second end of the ball spline shaft, wherein the collet chuck is adapted to receive a tool.

Abstract: A tool holder assembly and method for intentionally inducing modulation in a machining process. The tool holder assembly is configured for mounting in a tool block on a machining apparatus and includes a tool holder body configured to be secured to the tool block of the machining apparatus, a tool holder mounted on the tool holder body and configured for securing a cutting tool thereto, and a device for imposing a superimposed modulation on the tool holder so as to move the cutting tool relative to the tool holder body and thereby relative to the tool. The tool holder assembly is useful in a process for producing chips having a desired shape and size, and particularly to a method of controllably producing nanocrystalline chips.

Abstract: A glass working apparatus a casing, in which a rotating mechanism and an oscillating unit are installed. The rotating mechanism has a shaft rotatably mounted in the casing. The oscillating unit is connected with the shaft such that the oscillating unit is rotatable with the shaft. A glass cutting tool is connected to the oscillating unit, such that the glass cutting tool can be driven to rotate by the rotating mechanism through the oscillating unit and/or driven to oscillate by the oscillating unit for working on a glass workpiece.

Abstract: A drilling machine is provided for breaking chips formed by drilling action into manageable lengths. The drilling machine comprises a first gear having a first axis of rotation, and a cam follower surface. It has a second gear having a second axis of rotation coincident with the first axis of rotation. A housing is provided configured to support the first gear and the second gear, the housing having an undulating cam plate surface, a spring and a tool holder spindle having a third axis of rotation. The first and second gears are configured to impart both a linear feed and a rotation to the spindle. The first and second axes of rotation are coincident with the third axis of rotation such that the cam surface is urged into contact with the cam follower surface by the spring. The cam surface includes a plurality of steel balls positioned to follow the cam plate surface such that when the first gear rotates, the first gear is caused repeatedly to retract and then to advance, breaking chips that are formed.

Abstract: A drilling machine is provided for breaking chips formed by drilling action into manageable lengths. The drilling machine comprises a first gear having a first axis of rotation, and a cam follower surface. It has a second gear having a second axis of rotation coincident with the first axis of rotation. A housing is provided configured to support the first gear and the second gear, the housing having a cam surface, a spring and a tool holder spindle having a third axis of rotation. The first and second gears are configured to impart both a linear feed and a rotation to the spindle. The first and second axes of rotation are coincident with the third axis of rotation such that the cam surface is urged into contact with the cam follower surface by the spring. The cam surface and the follower surface are shaped such that when the first gear rotates, the first gear is caused repeatedly to retract and then to advance, breaking chips that are formed.

Abstract: In this process for drilling a bore (61), a drilling tool (11) is driven simultaneously in rotation about an axis (A) and in translation along the axis (A) in accordance with an advance movement. The advance movement is combined with an oscillating movement of the drilling tool (11) along the axis (A) of an amplitude sufficient to break up the swarf formed, while at the same time keeping the drilling tool (11) in the bore (61) which is in the process of being drilled. In certain exemplary embodiments, the application may be relevant to the aircraft construction industry.

Abstract: A drill has a tubular outer housing and a tubular inner housing. The inner housing is movable between extended and retracted positions. A pneumatic motor with a chuck mounts to the inner housing. Air pressure is delivered to annular pistons to cause the inner housing to extend and retract. Also, an annular hydraulic chamber with a variable orifice bypass controls the rate of feed. A processor records the total number of holes being drilled as well as recording the time duration for each hole.

Abstract: A pneumatic drilling machine is provided, comprising a pneumatic motor, a circuit for connecting the motor to a source of compressed air, a tool holder spindle, and a drive mechanism. The drive mechanism comprises a coupling shaft which can be moved to select a first mode of driving the spindle and a second method of driving the spindle. The mechanism has a driving cycle which comprises a stationary mode at the beginning and end of the cycle, and at least one phase for driving the spindle according to the first driving method, then a phase for driving the spindle according to the second driving method, then the stopping of the supply of air to the motor. A supply valve of the circuit is controlled pneumatically by the drive mechanism to interrupt the supply of compressed air to the motor at the end of the driving cycle.

Abstract: A boring control method for a machine tool for automatically boring a deep hole using a central control means performing boring with programmed control. In the boring, the number of processing and steps of the machine tool is kept minimum, load torque of a tool is detected continuously using torque detection means, and the movement of the tip portion of the tool desired for a piece of work is confirmed from a reference point to a hole bottom using a Z-axis movement device. The boring is continued in each step until the load torque exceeds a predetermined torque limit value, performed in a condition where a main shaft rotation number, or rotation speed of the tool, and feed speed form a specific pattern, and a condition is set where a total step number (f) does not exceed a predetermined limit step number (N).

Abstract: A pneumatic drilling machine is provided, comprising a pneumatic motor, a circuit for connecting the motor to a source of compressed air, a tool holder spindle, and a drive mechanism. The drive mechanism comprises a coupling shaft which can be moved to select a first mode of driving the spindle and a second method of driving the spindle. The mechanism has a driving cycle which comprises a stationary mode at the beginning and end of the cycle, and at least one phase for driving the spindle according to the first driving method, then a phase for driving the spindle according to the second driving method, then the stopping of the supply of air to the motor. A supply valve of the circuit is controlled pneumatically by the drive mechanism to interrupt the supply of compressed air to the motor at the end of the driving cycle.

Abstract: Method and apparatus for improving the efficiency of the rotating cutter of a tool by converting at least part of the rotational torque applied to the cutter to repeated rotational impact forces.

Abstract: A method for drilling a hole in a work piece, such as printed circuit boards, comprises drilling to a point in a work piece and retracting said drill bit a retract distance. The retract distance is configured such that a tip end of said drill bit remains below a top surface of said work piece. The method further comprises drilling a distance greater than said retract distance into said work piece.

Abstract: A hand tool apparatus uses a cutting tool with a first width and a tool axis to machine a hole in an object. The hole has a second width at least as large as the first width of the cutting tool. The apparatus includes a housing, a spindle unit in the housing for rotating the cutting tool and an orbital drive for rotating the spindle unit. An axial feed mechanism moves the orbital drive and the spindle unit jointly either toward or away from the object being machined.

Abstract: The invention provides a drilling apparatus and method for drilling a hole in a workpiece. The drilling apparatus includes means for rotating a drill bit and means for advancing the rotating drill bit into a workpiece to a first depth. The drilling apparatus further includes means for dwelling the drill bit within the workpiece at the first depth for a dwell time and means for further advancing the rotating bit to a second depth after the dwell time has expired. The drilling method includes rotating a drill bit and advancing the rotating drill bit into the workpiece to a first depth. The method farther includes dwelling the drill bit within the workpiece at the first depth for a dwell time and further advancing the rotating bit to a second depth after the dwell time has expired.

Abstract: The invention provides a drilling apparatus and method for drilling a hole in a workpiece. The drilling apparatus includes means for rotating a drill bit and means for advancing the rotating drill bit into a workpiece to a first depth. The drilling apparatus further includes means for dwelling the drill bit within the workpiece at the first depth for a dwell time and means for further advancing the rotating bit to a second depth after the dwell time has expired. The drilling method includes rotating a drill bit and advancing the rotating drill bit into the workpiece to a first depth. The method farther includes dwelling the drill bit within the workpiece at the first depth for a dwell time and further advancing the rotating bit to a second depth after the dwell time has expired.

Abstract: An apparatus having a controllable dwell for drilling and or countersinking a hole in a workpiece is provided which generally comprises a feed mechanism, a retraction mechanism, and a dwell mechanism. The feed mechanism is configured to feed a spindle from a starting position to a predetermined feed limit during a feed cycle. The retraction mechanism is configured to retract the spindle from the feed limit to the starting position to complete the feed cycle. The dwell mechanism is in communication with the retraction mechanism and comprises a mechanical bias member that stores energy during at least a portion of the feed cycle, wherein the mechanical bias member releases at least a portion of the energy once the spindle reaches the feed limit. The retraction mechanism is only actuated once the spindle reaches the feed limit and the mechanical bias member releases at least a portion of the energy.

Abstract: This pneumatic machine tool includes a driving shaft (14) driven in rotation by pneumatic drive means (12), a driven tool-carrier shaft (16), a gear mechanism (18) disposed between the driving shaft and the driven shaft to drive the latter, a set of sensors (22) for measuring operating parameters of the machine tool, and a central control unit (20) in which are stored algorithms for controlling machining as a function of data received from the sensors, the gear mechanism including means (24, 26, 28, 30) for changing the gear ratio. The gear mechanism includes primary and secondary sets (24, 26) of toothed wheels with different demultiplication ratios, each adapted to rotate freely relative to the driving shaft (14). The speed changing means include a positive clutch (28) constrained to rotate with the driving shaft (14) and axially mobile relative thereto between two end positions in which the positive clutch (28) is engaged with respective sets of toothed wheels (24, 26).

Abstract: A mounting attachment for a penetrating tool such as a drilling head on a machine with a machining shaft includes a support provided with means for coupling to a machine; a tool holder provided with means for fixing a tool; means for axially guiding the tool holder relative to the support; means for linking in rotation the tool holder and the support; and elastically deformable suspension means for suspending the tool holder from the support, the suspension means allowing axial translation and self-sustaining reciprocating or vibrating axial movements of the tool holder resulting from a controlled displacement of the support with respect to a workpiece.