Ford Motor Company Limited

The Ingersoll Milling Machine Company

Thomas J Lindem

Richard Ogletree

Daniel M Mills

Paul A Charles

Jan Van Roojen

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. The preferred frame is a stationary, box-type stue which encompasses the gantry and spindle, and the frame provides an enclosed space protecting the linear motors.

Symmetrical multi-axis linear motor machine tool

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. The preferred frame is a stationary, box-type structure which encompasses the gantry and spindle, and the frame provides an enclosed space protecting the linear motors.

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.

Octahedral machine with a hexapodal triangular servostrut section

A method of machining simultaneously a sequence of surfaces on each of multiple sides of a workpiece, comprising: (a) supporting a plurality of rotary-driven spindles, each carrying a cutting tool, each spindle being supported by a plurality of relatively movable elements that provide for movement into and out of a predetermined sized, cubed machining space, such support providing for spindle movement having vectors along at least mutually perpendicular axes; (b) placing the workpiece in the machining space at a predetermined location; (c) actuating relative movement of the elements by use of linear motors to accurately position each spindle for simultaneous machining of first surfaces on separate sides of the workpiece; and (d) actuating the elements by use of said linear motors to reposition the plurality of spindles for simultaneous machining of other surfaces on each of the separate sides of the workpiece.

Method for multiple-spindle machining

A multiple-axis machine for positioning a rotary-driven spindle, such positioning being by use of linear motors. The machine has a support for defining multiple axes, with (i) a rigid vibration-dampening bed defining at least an X-axis; (ii) at least one hollow column defining a Y-axis and having one end adjacent and movable along the bed and the other end extending away from said bed; (iii) a slide adapted for movement along the Y-axis of the column; (iv) a cage rigidly fixed to the slide for defining a Z-axis way; and (v) a hollow ram slidable within the cage and along the Z-axis way and carrying the spindle. The machine has bearing assemblies interposed between the column one end and the bed, between the column and slide, and between the cage and ram to provide for respective relative movements along the axes, the bearing assemblies being preloaded to provide an interference fit of 10-20% of the maximum bearing loading. Linear motor assemblies are interposed between the column one end and bed, between the column and slide, and between the cage and ram, the linear motor assemblies are selectably actuatable to impose a linear thrust force upon any or all of the column, slide, or ram for respective movement along the axes. The ratio of the natural frequency of the support and bearing assemblies to the bandwidth of the control velocity loop is slightly greater than one.

Multi-axis linear motor positioner with Y-axis supported at single end

A machining system that has (i) plural machining cells spaced along a path, each having a single-point-tool and a rapid-positioning assembly for positioning the tool for multiple insertions into a workpiece as well as rapid tool exchange at speed rates that approach or exceed one G; (ii) table means for presenting a table surface in a selected plane for each cell; (iii) workpiece means for each table surface having keying surfaces for lockingly mating with a reference point of such table surface; (iv) transfer means for rapidly replacing a machined workpiece with an unmachined workpiece on a table surface, the just-machined workpiece being transferred to the next table surface while the substituted workpiece is undergoing machining; and (v) programmed electrical control means for activating the positioning assemblies and transfer means. A method of machining, comprising: (a) locking a workpiece on a fixture having dimensional keys and releasably securing such fixture on an adjustable worktable in a predetermined first position facilitated by said keys; (b) adjacent each worktable, rapidly positioning a rotary single-point-tool for linear feed into a first of said workpiece surfaces while in a first position, said positioning being carried out at accelerations/decelerations of at least about one G; (c) feeding the rotating tool into the workpiece to carry out machining at speeds of 1-1300 inches per minute for drilling and boring, and at least about 5000 sfm for milling; (d) after withdrawing the tool from the workpiece, repositioning the single-point-tool for another linear feed into other workpiece surfaces or transfer to another tool.

Multi-positioner machining system

A machining system that has (i) plural machining cells spaced along a path, each having a single-point-tool and a rapid-positioning assembly for positioning the tool for multiple insertions into a workpiece as well as rapid tool exchange at speed rates that approach or exceed one G; (ii) table means for presenting a table surface in a selected plane for each cell; (iii) workpiece means for each table surface having keying surfaces for lockingly mating with a reference point of such table surface; (iv) transfer means for rapidly replacing a machined workpiece with an unmachined workpiece on a table surface, the just-machined workpiece being transferred to the next table surface while the substituted workpiece is undergoing machining; and (v) programmed electrical control means for activating the positioning assemblies and transfer means.

Positioning apparatus for multiple-spindle machining, comprising: (a) a plurality of upstanding columns rigidly interconnected to a common platform and aligned parallel to each other and perpendicular to the platform within an accuracy of .+-.0.0005 inches; (b) rail means extending between each of the columns along the periphery defined by the footprint of the columns for providing movable support and having bearing means on the columns providing for movement of each rail means along the Y-axis; (c) other movement means slidable on each of the rail means along at least another axis of movement; (d) linear motor means for selectively moving the rail means and other movement means along said respective Y and another axis at peak accelerations or decelerations of about 1-2 G's; and (d) spindle means on each ram having a spindle rotationally driven about an S-axis thereof.

Positioning apparatus for multiple-spindle machining

A mounting for supporting a cutter tooth in a boring bar for fine adjustment outwardly to compensate for tooth wear, the mounting including a cartridge insertable into a hole through the boring bar to support the tip of the cutter tooth in a cutting position with respect to the bar. The cartridge comprises a slidable holder connected by means of a differential screw to a nut so that, as the screw is turned, the length of the cartridge is increased to provide fine adjustment in the position of the cutter tooth. Coarse adjustment in the position of the cutter tooth is provided as an incident to assembling the parts of the cartridge by threading the screw into the nut until the lower end of the screw is flush with the lower end of the nut and by then mounting the holder on the upper end of the screw. Once assembled as a unit, the cartridge is inserted into the hole until an annular shoulder on the nut seats against a complimentary shoulder within the hole thereby accurately locating the cutter tooth so only fine adjustment is needed thereafter. In order for the mounting to be used in smaller diameter boring bars, one form of the invention utilizes a differential screw having interfitting male and female portions and, in the other form of the invention, a driver recess in the lower end portion of the screw permits the latter to be positioned essentially flush with the underside of the boring bar.

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Rockford, IL, United States of America

Thomas J Lindem