Abstract: The tools of the various machining heads are housed on a common drum, which is remote from the heads and rotated to select a given row of tools. At each head, there is provided and intermediate station having a container housing a row of tools; and a shuttle provides for sequentially transferring the tools between the drum and the intermediate stations. Each container is rotated 90° between a position cooperating with the shuttle and a position cooperating with a device for exchanging the tools between the head and the container. The container is also movable with respect to the device to select the location of the tool to be changed.

Abstract: The drilling machine has a cross member along which slide two carriages supporting two machining heads; the two carriages are moved independently of each other along the X axis; one of the two machining heads is fitted to the respective carriage by means of a slide which is also moved along the Y axis by an electric motor controlled by a numeric-control unit; the maximum travel of the slide is at least twice the pitch of the rows in the matrix of holes in the printed circuit boards; and the movement of the slide provides for both setting the two machining heads along the Y axis, and enabling the two machining heads to simultaneously drill two adjacent rows in the matrix of holes.

Abstract: The tools of the various machining heads are housed on a common drum, which is remote from the heads and rotated to select a given row of tools. At each head, there is provided an intermediate station having a container housing a row of tools; and a shuttle provides for sequentially transferring the tools between the drum and the intermediate stations. Each container is rotated 90.degree. between a position cooperating with the shuttle and a position cooperating with a device for exchanging the tools between the head and the container. The container is also movable with respect to the device to select the location of the tool to be changed.

Abstract: The machine tool featuring a number of machining heads for machining printed circuit boards has a worktable movable along the Y axis, and two rows of four machining heads fitted to a common carriage movable along the X axis. The circuit boards are arranged in packs, each having two locating pins for aligning and locking the pack to a respective rectangular fixture fitted to the worktable with the short side parallel to the Y axis. Each pair of heads is provided with a pair of tool-change devices and a common tool store, which is defined by one or two boxes removably insertable inside respective supports fitted to the carriage; three pairs of tool-change devices are housed inside gaps between adjacent pairs of fixtures; and a further two pairs of tool-change devices are located adjacent to the end fixtures.

Abstract: The machine has a device for exchanging tools between a tool store and the spindle of a machining head carried by a carriage movable along the X axis; the store has a number of locations for the tools arranged in a matrix of rows and columns; a worktable is movable along the Y axis; and the tool-change device and the store are movable with respect to each other to select the required tool. For which purpose, activatable means are provided to enable the carriage to command the relative movement of the device and the store. A support, movable parallel to the X axis, is engaged by an element carried by the carriage to enable the support to be moved in a given direction in opposition to the action of return springs for restoring the support to a rest position.

Abstract: The device includes an operating head movable by a control unit with respect to a board for machining; the operating head includes a board holder device and an electric motor for a tool spindle; the rotor of the motor rotates with respect to the stator on air-cushion supports, and the stator slides axially on a further air-cushion support and is insulated with respect to the operating head; a signal generator senses the capacitance between the rotor and the stator, and generates an electric signal upon the tool on the spindle contacting the upper surface of the board; and the signal is used to define a reference dimension relative to the upper surface, and to so condition the control unit as to feed the tool to a predetermined depth as of the upper surface.

Abstract: The drilling unit comprises a cross-piece secured to the base and two carriages supporting said two operating heads and sliding on said cross-piece. The two carriages are each displaced independently of one another along the axis by means of two nut and screw pairs, each of which is associated with one of the carriages. The screw of each nut and screw pairs is actuated by a corresponding reversible electric motor mounted on the cross-piece, whereas the nut is mounted on the corresponding carriage displaced outwards with respect to the head so as to allow the heads to move individually into a common machining zone on the table.

Abstract: The device presents a number of supports associated with a number of machining heads and located at the front of the machine. For each machining head, the supports are located on two superimposed surfaces for respectively supporting a pack of boards for loading and a pack of boards unloaded off the work table. The supports are fitted to a frame which is moved vertically to position the two surfaces at the table, and which is also movable laterally for enabling access to the machine. The device also presents a cross member movable along the Y axis; and a number of arms for alternately engaging two opposite edges of the packs and transferring them between the table and the supports. The arms are connected to a common connecting rod which is moved to rotate and withdraw them clear of the packs during the idle movement of the cross member.

Abstract: A machine presenting a worktable movable along a first axis; and a crosspiece fitted with a number of machining heads and movable along a second axis perpendicular to the first axis. The crosspiece presents a box structure, and two end portions guided on two horizontal appendixes of two fixed uprights. Between one of the appendixes and the corresponding end portion of the crosspiece, there is provided a screw-nut screw pair for selectively moving the crosspiece. Each machining head is assigned a tool store accessible from the rear of the machine.

Abstract: A machining head presenting a hollow body in turn presenting a first crosspiece with a seat for supporting in sliding manner a motor-driven tool spindle. The body also presents a second crosspiece fitted with means for axially displacing the spindle which may be of different lengths and is driven by an electric motor via a screw-nut screw pair located between the second crosspiece and a third crosspiece connected removably to the spindle. The second crosspiece presents an end portion pivoting by means of a pin on an appendix of the hollow body, and is fitted to the body by means of a pair of locating pins and a pair of screws. By disconnecting the third crosspiece from the spindle and rotating the second crosspiece about the pin, the spindle may be changed without removing the machining head from the machine. The locating pins are removed from their respective seats by means of a key in the form of a screw and normally housed in a seat on the crosspiece.

Abstract: The tool store comprises a prismatic drum having a number of cells in which the tools may be inserted singly or housed inside a magazine; and the tool change device comprises a pair of clamps operated singly and fitted to the work table. The clamps are moved simultaneously in a direction perpendicular to the axis of the drum, for withdrawing or loading the tool from/on to the drum or spindle; the tool being transferred between the drum and spindle by the work table; and a sensor being provided for detecting the tip of the tool inserted in the spindle and so adjusting the axial position of the tool in the spindle.

Abstract: On a drilling machine for drilling packs of printed circuit boards, the packs are loaded and unloaded between a support and the work table by engaging a pin on the pack via a pair of jaws and by moving the table longitudinally. The pack is retained by a bar for enabling two bars to engage and locate a further pin on the pack; further retaining elements provide for sliding the pack in relation to the table; and a member is activated for aligning the pack against a fixed locator. The support forms part of a rack operated vertically in steps by a lifter located behind the drilling machine.

Abstract: An air pad comprising a body with two opposite faces, and having a number of supporting orifices on one face and at least one compensating orifice on the other face, each compensating orifice being located on a micropad comprising a plate integral with a shank sliding in a cylindrical chamber communicating with the supply conduits of the orifices; and the plates cooperating with a surface opposite the surface of the slideway and located on a bar fitted to the slideway.

Abstract: The device is provided on a machine tool, wherein the drilling or milling operating head (12) comprises an axially movable spindle (14) and a workpiece hold-down (17), and wherein the working depth is controlled according to the relative position of the tool (16) with respect to the hold-down (17), defined by sensing a reference member (56) by means of the tool (16). To avoid the errors due to the thermal expansion in defining the reference position between the tool and the hold-down, before the reference member (56) is sensed, an electric power supply heats the spindle (14) by sequentially energizing the phases of the statoric coil of the spindle electric motor (76). The reference member (56) comprises a proximity sensor (64) operated by the tool (16) through an air pad piston (67).

Abstract: Contouring of a stack of one or more circuit boards is effected by first partially cutting the contour, leaving a portion of the contour long enough to ensure the rigidity of the circuit with respect to the board. The circuit is then clamped, while the remaining portion is cut without any discontinuity in the cutting. The machine comprises an operating head and a workpiece pressing pad which is operated for clamping the circuit during the cutting of the remaining portion of the contour. The pad is movable with respect to the head in a direction parallel to the uncut portion of the contour for displacement at least equal to the length of such portion. After the cut, as the head is raised, the pad is returned to rest position by the camming action of a roller against a sloping edge.

Abstract: To reduce dead times and waste of dummy boards necessary for preparing individual packages of stacked boards to be drilled, the latter are loaded on the table in a single stack and are drilled from the top in groups formed of a predetermined limited number of boards, drilling only partially into the next board to be drilled. The drilled boards are carried out of the stack which is reapproached to the drilling head. The drilling restarts by following the impression left by the tool in the preceding cycle on the partially drilled board. The numerically controlled drilling machine includes a table vertically movable to bring the stack against a fixed stop. A slide transversely movable after each drilling cycle engages the already drilled boards and carries them to an unloading support external to the table.

Abstract: The drilling machine comprises a pair of cross slides formed of two parallelepiped blocks of granite connected as a T above a horizontally stationary board carrying table. The transverse block carries two operating heads and, by means of pneumostatic bearings, guides their movement along the X-axis. The other block is guided by the machine frame by means of other pneumostatic bearings. Each head carries a spindle operable to lock and unlock the tool to permit automatic tool replacement from a corresponding tool magazine with provision for checking the integrity of the engaged tool. One of the heads can be disengaged from the X-axis servomotor and connected to the other one at a predetermined distance. Two series of equal printed circuit supports can be drilled simultaneously by using a single package of boards to be cut after the drilling or the etching. Tool changing and tool integrity checking operations can be effected simultaneously for the two operating heads.