Abstract: A machining system and method of machining are provided for machining large, heavy workpieces, such as large aircraft components, that are oriented vertically affixed on a vertical, on-edge pallet. The machining system includes an upstanding workpiece support to which the transportable pallet is clamped. The pallet is large enough to support the large workpiece but is still relatively thin and light so that it can be easily transported to the machining station where the more massive workpiece support is located. The pallet lacks the necessary stiffness for accurate machining of the part thereon. The much thicker upstanding support is utilized to provide the pallet and affixed part the necessary stiffness when the pallet is clamped thereto, by a magnetic clamping arrangement. The magnetic clamping provides quick assembly and disassembly of the pallet with the support stand thereby decreasing cycle time and increasing production rates.

Abstract: A machine tool has a frame supporting a vertical gantry which is driven at the top and bottom sides of the gantry such that the opposed, normal magnetic forces between stator coils and magnets are substantially equal and are self-cancelling. This reduces normal magnetic forces that increase friction, and this prodes symmetry along an X-axis. A spindle-carrying saddle travels in a vertical slot in the center of the gantry with left and right linear motors mounted on opposite sides of the gantry. The linear motors are identical so that opposed right and left-hand, normal magnetic forces are self-cancelling. This provides symmetry along the vertical Y-axis. A spindle and ram are mounted on the saddle and are driven by at least one linear motor to travel along the Z-axis. The symmetry and cancelling of normal, magnetic attractive forces reduces the weight and the amount of forces needed to accelerate the gantry in the X-direction and the saddle in the Y-direction.

Abstract: A machine tool assembly, and particularly a spindle unit therefor, is provided wherein the spindle unit is relatively small and is designed to run at rotary speeds of between 30,000 rpm's and 40,000 rpm's utilizing hydrodynamic bearings for the spindle shaft. The hydrodynamic bearings are effective to take increased loads versus similarly sized conventional metal-to-metal contacting bearings to provide a very stiff machining system even with the higher loads generated by the increased rotary operating speeds for high speed machining contemplated for the spindle unit herein. The bearings are also designed to use a water-based fluid which is compatible with the cutting fluid. Non-contacting fluid barrier seals limit and control the amount of bearing fluid leaked to the cutting fluid. Due to the compatible nature of the two fluids, small fluid leakage from the bearings will not hurt the cutting fluid. The cutting fluid circulated at an ambient inlet temperature, e.g., 70.degree. F.

Abstract: A machine tool has a frame supporting a vertical gantry which is driven at the top and bottom sides of the gantry such that the opposed, normal magnetic forces between stator coils and magnets are substantially equal and are self-cancelling. This reduces normal magnetic forces that increase friction, and this provides symmetry along an X-axis. A spindle-carrying saddle travels in a vertical slot in the center of the gantry with left and right linear motors mounted on opposite sides of the gantry. The linear motors are identical so that opposed right and left-hand, normal magnetic forces are self-cancelling. This provides symmetry along the vertical Y-axis. A spindle and ram are mounted on the saddle and are driven by at least one linear motor to travel along the Z-axis. The symmetry and cancelling of normal, magnetic attractive forces reduces the weight and the amount of forces needed to accelerate the gantry in the X-direction and the saddle in the Y-direction.

Abstract: An integrated spindle and motor unit includes a housing containing both the spindle shaft and motor with hydrostatic bearings around the front and rear of the spindle shaft. The hydrostatic bearings utilize high pressure oil, preferably in the range of 1,200-1,500 psi and provide good load bearing capacity and increased stiffness for improved cutting accuracy when cutting within the full range of cutting speeds. The present spindle unit is designed to be run at high speeds. The front and rear hydrostatic bearing pads are closely axially spaced along the spindle shaft so that the dynamic stiffness of the spindle is increased to avoid resonant vibrations even at high speed operation thereof. The spindle unit incorporates a sealing system utilizing a series of non-contacting seals including a labyrinth seal and aerostatic floating ring seals which keeps bearing oil in the spindle.

Abstract: A target is provided for attachment to a milled locator surface on a machine or to a fixture carrying a part to be machined. A plurality of spaced targets may be used to establish a datum plane. The target has an outer planar flat surface to be engaged by an indicator or used with a laser positioner device. The outer planar flat surface is located at a fixed distance from the milled locator surface, and this distance is usually recorded by indicia on a plate adjacent the indicator or on a cover that covers and protects the target. The outer target surface is parallel to the milled locator surface. To achieve this, the body of the target has inner, planar precisely finished surface that is parallel to the outer planar surface which is on the end of a threaded shaft. The precisely finished, inner planar surface is abutted against the milled surface on the tool or fixture. Anti-backlash springs remove any play from the threaded engagement.

Abstract: The tape laying head disclosed mounts the laydown rollers for steerability as a unit independently of the steering of the tape head as a whole. The separate steerability of the laydown roller unit is utilized for adaptive steering control in response to edgewise drift of the tape during normal tape laying, as determined by tape edge sensors. When laying tape along a curved path other than the natural path of the tape in free-rolling movement, the laydown roller unit is steered in counterrotation to the steering of the tape head as a whole, thereby to cause a relative axial shift of increments of the tape across its width, enabling the tape to lie flat along a curved course on the lay surface.

Abstract: In a cutting machine having an octahedral framework, a cutting tool is carried by a servostrut support having a platform mounted on extendable and retractable struts. In order to reduce deflections and to limit transfer of bending moments, from the servostrut support to the other connected support sections of the framework, the six struts are mounted at pivot mounts such as ball joints in a triangular support. Three of the pivotal mounts are positioned in a first triangle and in corners of the triangle support, and the other three struts are positioned in a second larger triangle in the triangular support. The nominal axis of rotation of spindle drive for the cutting tool may be either about nominal horizontal axis, a nominal vertical axis or a nominal 45.degree. axis. Several frameworks may be arranged to define a hollow tunnel with platforms projecting their cutting tools from opposite sides of the transfer tunnel.

Abstract: A machine element support comprised of a plurality of axially extensible and contractible servostruts which are individually adjustable and collectively controllable. The struts comprise an outer tubular member and a slidably, interfitted, elongated, inner member. The powered servostruts are movably connected to an machine element such as a spindle head by one of the members on one end and to a rigid machine tool frame by the other of the members on the other end. Linear position sensors mounted on the servostruts serve to precisely measure strut extension and retraction for feedback control purposes. A preferred servostrut configuration is a hexapodal array, in which two servostruts are mounted side by side in each of the three well-known orthogonal axes of machine tool practice, providing six-axis movement and positioning of the tool head or workstation relative to the workpiece.

Abstract: An apparatus and method of building a machine system having a plurality of cutting machines involves a taking of the final print tolerance and budgeting and using the tolerances for fixtures and machines in a manner to determine stiffness requirements and tolerances for such as tool cut depth, tracking of feed slide and perpendicularity of the spindle face. To gauge very fine tolerances, special reference datum surfaces are provided on the fixtures and machines to provide a "granite" plane from which very precise measurements may be made to set up initially the machine with the assigned tolerances. Indicators can be mounted on the spindle to sweep the targets on the fixture to level the spindle face to very fine tolerances. An indicator traveling with cutting head along a feed slide may sweep targets on the fixture and a tracking means may be adjusted to a precise tracking tolerance.

Abstract: High speed cutting with machine tools is achieved with readily available bearings of a small diameter by mounting and presetting the cutting tool directly in a spindle of a spindle unit without employing a tool holder. Preferably, the spindle unit is small like a tool holder and can be easily changed with conventional kinds of tool changing apparatus. The elimination of the tool holder allows the conventional bearings to be kept small so that they may be operated at high speeds, e.g., 20,000 to 40,000 rpm, without excessive heat that would damage the bearings.

Abstract: A machine tool frame is disclosed which is comprised of twelve struts connected together at their ends in six nodes to define the eight triangular panels of an octahedron. Forces generated by the operation of the machine tool are received by the frame at its nodes, being the nodes of opposed parallel triangular panels, upper and lower, in the specific examples illustrated. The octahedral frame displays superior rigidity due to its inherently closed kinematic loop, and to the virtual absence of bending stress in its constituent members accomplished by nodal loading. Movable machine elements are mounted upon six extensible and retractable servo-struts emanating in pairs from the nodes of a given triangular panel of the octahedral frame while opposing fixed elements located within the octahedral frame are supported tripodally from the frame nodes associated with a single triangular panel of the frame.

Abstract: The invention relates to a high speed turning machine for machining a rotating workpiece to have a predetermined profile surface by using a cutting tool mounted on a pivotal tool holder that is reciprocated rapidly toward and from the workpiece surface. An armature of a linear motor is mounted on the pivotal toolholder. The toolholder is mounted in frictionless bearings. The armature is positioned on the toolholder relative to the tool and its pivot axis to provide a substantial mechanical advantage.

Abstract: A method and apparatus for aligning an actual surface with the internal coordinate system of a machine working thereon is disclosed. A part program controls the motions of a tape laying machine for depositing composite tape on the surface of a mandrel marked with a plurality of reference points. A probe assembly is attached to the tape laying head of the machine and can be used to measure the coordinates of the reference points on the mandrel surface relative to the internal coordinate system of the machine. These measurements and corresponding points on a representative surface permit a transformation function to be generated based upon the rotation and translation of one surface with respect to the other. The geometric data of instructions of the part program are transformed from their orientation relative to the reference surface to a new orientation relative to the mandrel surface by the transformation function before being applied to the tape laying machine.

Abstract: A laser-optical gauging system is disclosed for measuring the diameter of the cutting path of a rotary cutting tool while rotating in the machine spindle at speeds approximating the desired cutting speed for the intended cut, and for determining the axial location of the tip of a tool.

Abstract: A tape laying machine for depositing composite tape on the surface of a mandrel having a tape laying head positionable in multiple axes by a linear interpolative feedback control in combination with an adaptive control. The feedback control receives a commanded position from a natural path part program and regulates motion of the tape laying head of the machine along a track which will not unequally tension the edges of the tape and which is highly reproducible. The adaptive control separately varies the motion produced along individual axes by the feedback control without changing the tracking path to ensure correct tape laying conditions.

Abstract: Disclosed is a machine system adaptable to a wide range of milling conditions and functions by the provision of a master milling head capable of providing spindle-driving power and up to 5-axis movement to a wide range of individual spindle heads each designed for a specific machining function, and each selectively, interchangeably, and automatically matable to the master head.

Abstract: A tape placement method and apparatus for producing laminated articles from composite tape. The tape placement apparatus builds plies of a laminated article by laying courses of composite tape along natural or untensioned paths of a compound contoured surface. The natural paths are determined by a path generation routine which incrementally fits an untensioned path to a compound curved surface and outputs the data as a desired path for a tape course. The natural paths are generated as nonmachine specific geometric data which are translated into a machine instructions which cause controlled motions of the tape laying head of the tape placement apparatus. The translation into machine instructions includes an alignment process whereby variations in the orientation of the contoured surface can be corrected.

Abstract: The invention contemplates the provision of a double-shelled dust-collecting hood for a high-speed rotary cutting tool. The outer shell seals itself to the workpiece while the inner shell stands clear of the workpiece. The outer shell is open-ended so that the flow of air induced by a suction port within the hood enters at the unsealed end of the outer shell and reverses direction as it turns into the inner shell.

Abstract: An involute external tooth profile is cut into the periphery of a gear blank by positioning a rotating milling cutter with its cutting path perpendicular to the plane of action of the desired base surface of revolution within the gear blank so as to penetrate the plane of action from the side thereof opposite to the base surface and with a predetermined line of intersection which generates the involute profile as the base surface rolls upon the plane of action. The rolling action causes the generating line to traverse the blank between its addendum surface and a depth sufficient to provide the desired length of active profile.