Meltable matrix chucking machining center and process using

A two-stage process for chucking and machining, relative to parallel, precisely-spaced planes of reference, a metal blank having two generally opposite principal surfaces, comprising, in its first stage, the steps of

• meltable-matrix chucking said blank by one such principal surface to a meltable matrix chuck having means to locate a first plane of reference, and
• machining the upward-presented second principal surface of the blank according to a machining program predetermined relative to such first plane of reference,
• positioning in registration with said first chuck, a second meltable matrix chuck having means to locate a second plane of reference, so that its plane-of-reference locating means is parallel to that of the first chuck moving one or the other of said parallel chucks to a precise chosen spacing, whereby to correlate a subsequent machining program with that program above mentioned,
• then, with said first chuck inverted to present said newly-machined surface downward, meltable-matrix chucking said blank to said second chuck while maintaining hard the matrix material in said first chuck,
• reversing the positions of both chucks and melting away such first chuck material while maintaining hard such material in the second chuck,
• machining the upwardly-presented first principal surface of said blank relative to such second plane of reference according to such subsequent machining program, and
• melting away the matrix material from said second chuck.

For the programmed machining and inspection of metal blanks of the type having two generally opposite principal surfaces and whose width, between forward and rear edges, is greater than its thickness between said principal surfaces, the combination comprising

• (A) track means for conveyance, to the machining and inspection centers hereafter defined, of a meltable matrix chuck holding a metal blank for machining,
• (B) a chucking center including
• a rotary barrel frame and means to support said barrel frame along a horizontal pivot axis,
• a first track portion on said barrel frame extending parallel to the pivot axis, and including means to support a meltable matrix chuck and establish for it a first generally horizontal plane of reference at a radial distance from said horizontal pivot axis, as well as means to establish the transverse location of a chuck thereon,
• the barrel frame having means to position said first track portion at a base level aligned with said track means,
• an alternate track portion supported on said barrel frame 180.degree. removed from said first track portion, said alternate track portion including means to support a meltable matrix chuck inverted relative to said first mentioned chuck support, and including means to establish, for a chuck thereon, a second plane of reference parallel to the first and the transverse location of a chuck thereon,
• means to turn said barrel frame 180.degree. about said horizontal pivot axis, and
• means to adjust the spacing of said alternate track portion from said first track portion, whereby chucks supported within said barrel frame, inverted relative to the other, may be brought from juxtaposed position, at which their planes of reference are at a chosen spacing, to a clearance position at which either said first track portion or said alternate track portion may be at such base level,
• (C) a pair of meltable matrix chucks whose plan forms are generally coincident with that of such blank, each being of the type having a normally upward surface fillable with meltable matrix chuck material and having downward-facing means for positioning at such first or second plane of reference and means to mate with the transverse locating means of one said track portion,
• the said fillable surfaces of said chucks being provided with continuous grooves,
• port means for permitting the inflow, into said continuous grooves, of molten matrix material, and
• heater and refrigerant-conducting means accommodated and releasably secured within said grooves and leading to and having disconnect fittings outward of said chucks,
• said grooves being of substantially greater cross-section than that occupied by said heater and refrigerant-conducting means, in combination with
• removable means, fittable along edges of each said chuck, to dam against corresponding edges of such blank, whereby to contain molten matrix material filled beneath a principal surface of the blank,
• (D) means, of sufficient flexibility to permit such 180.degree. turning of said frame, to deliver refrigerant to and to provide heat energy to meltable matrix chucks when so supported within said frame,
• (E) a machining center for metal blanks so chucked, comprising
• a machine tool having a power cutter movable at least vertically, longitudinally and in a transverse direction,
• a tilt table having track means extending longitudinally, which track means serve also to establish a plane of reference,
• whereby a chuck having means for positioning at such plane of reference may be affixed longitudinally along said track means,
• said tilt table portion having a tilt axis parallel to such plane of reference,
• means to tilt said tilt table portion while said cutter is cutting, together with
• means, adjacent to one end of said tilt table, to mount same on a swing axis generally perpendicular to said tilt axis, and means to move said tilt table in reversing arcs about said swing axis,
• whereby such cutter movements and the table tilting and swing movements may be coordinated and directed according to an automated machining program, and
• (F) an inspection center for metal blanks so chucked, comprising
• measuring means movable at least vertically, longitudinally and in a transverse direction,
• means to record measurements taken at intervals,
• a tilt table having track means extending longitudinally, which track means serve also to establish a plane of reference, whereby a chuck having means for positioning at such plane of reference may be affixed longitudinally along said track means,
• said tilt table having a tilt axis parallel to such plane of reference,
• means to tilt said tilt table, and
• means, adjacent to one end of said tilt table, to establish a swing axis, generally perpendicular to said tilt axis and means to move said tilt table arcuately about said swing axis,
• whereby movements of said measuring means and the tilt table tilting and swing movements may be coordinated and directed to provide a series of inspection positions according to an automated inspection program.

For machining metal blanks chucked substantially longitudinally in meltable matrix chucks,

• a machining center comprising
• a machine tool having a power cutter movable at least vertically, longitudinally and in a transverse direction,
• a tilt table having track means extending longitudinally, which track means serve also to establish a plane of reference,
• whereby a chuck having means for positioning at such plane of reference may be affixed longitudinally along said track means,
• said tilt table portion having a longitudinal tilt axis parallel to such plane of reference, and
• means to tilt said tilt table portion while said cutter is cutting, in combination with
• means adjacent to one end of said tilt table, to mount same on a swing axis generally perpendicular to and intersecting said tilt axis, and means to move said tilt table in reversing arcs about said swing axis,
• whereby such swing movements may be coordinated with such tilt movements.

For inspecting metal blanks chucked substantially longitudinally in meltable matrix chucks,

• an inspection center comprising
• measuring means movable at least vertically, longitudinally and in a transverse direction,
• means to record measurements taken at intervals,
• a tilt table having track means extending longitudinally, which track means serve also to establish a plane of reference, whereby a chuck having means for positioning at such plane of reference may be affixed longitudinally along said track means,
• said tilt table having a longitudinal tilt axis parallel to such plane of reference, and
• means to tilt said tilt table about said tilt axis, together with
• means, adjacent to one end of said tilt table, to mount same on a swing axis generally perpendicular to and intersecting said tilt axis and means to move said tilt table arcuately about said swing axis.

A process of utilizing a program for both chucking and machining one principal surface and a forward or aft edge of a metal blank having two generally opposite principal surfaces, comprising the steps of

• supporting, at a meltable matrix chucking station, a meltable matrix chuck, said chuck and its said support together having means to establish a plane of reference for such program, and together having longitudinal slide guide means, parallel to such plane, to position such chuck in a predetermined transverse position relative to such longitudinal slide guide means,
• positioning the blank with the other principal surface, being the surface not immediately to be machined, presented toward and spaced above the fillable surface of said chuck,
• chucking the blank by filling molten matrix material upon said chuck to at least the level of said other principal surface and causing said matrix material to harden and adhere to said surface,
• then removing said chuck from such chucking station and
• locating and securing it in a machine tool having, together with said chuck, support means to re-establish a corresponding plane of reference and having longitudinal slide guide means, parallel to said plane, to re-position said chuck in a corresponding predetermined transverse position,
• machining, relative to such re-established plane of reference and such transverse position, to substantially final contour that principal surface of the blank which is presented outward from said chuck, and while so machining, tilting the chuck on an axis parallel to said slide guide mcans, to raise at least one such forward or rear edge and on such raising to machine the edge so raised,
• whereby such tilting to raise affords access for machining the edge or edges so raised,
• and releasing the blank so machined from the chuck.

The process of utilizing an integrated machining program for making a two-piece hollow metal airfoil, each of which pieces has two opposite principal surfaces, namely an exterior airfoil surface and a hollow interior surface bordered by edge portions for adhered mating, comprising the steps of

• a. chucking in a meltable matrix chuck having plane-of-reference establishing means and relative to a first plane-of-reference for said blank, a metal blank by that surface of the blank which on subsequent machining will be its interior airfoil surface,
• b. machining its opposite surface according to said machining program and relative to said first plane-of-reference for said blank, to form its exterior airfoil surface,
• c. inverting said chuck over a second meltable matrix chuck having plane-of-reference establishing means so that the planes-of-reference of said chucks are parallel,
• d. bringing said parallel chucks to such predetermined spacing as to establish a second plane-of-reference for said blank at a predetermined distance from its said first plane-of-reference,
• e. at said spacing, chucking the surface machined according to step 6 in said second chuck,
• f. releasing the blank from said first chuck whereby to present the released surface for machining,
• g. machining said released surface, according to said machining program relative to said second plane-of-reference to form such hollow interior surface so bordered by edge portions, and permitting the piece so machined to remain chucked by its exterior surface,
• h. repeating the steps a-g for a second blank relative to first and second planes-of-reference for said second piece, and thereby providing a second machined piece for said airfoil which piece is chucked by its exterior surface,
• i. applying adhesive to said machined edge portions and so positioning the two chucks in registration with each other that their planes-of-reference are parallel and pressed against each other at a predetermined spacing,
• k. while so exerting pressure at said spacing, curing such adhesive, whereby to adhere the two machined pieces to each other and establish a precisely determined airfoil thickness, and
• l. releasing the adhered airfoil from said chucks.