Patent ID: 11897074
Assignee: THE BOEING COMPANY
Field: Machine tools (Mechanical engineering)
Classification: CPC B | IPC B

Claim 9:
10. A method of forming a plurality of perforations in a thin sheet of a composite material, the method comprising:
positioning a surface of the thin sheet with respect to the needle array according to claim 1, wherein the needle array is operatively coupled to an ultrasonic drilling apparatus such that the needle array is positioned above a first region of the thin sheet,
repeatedly contacting the surface of the thin sheet within the first region with the needle array at an operating frequency of above 20 kHz for a period of time sufficient to form a first plurality of holes in the first region of the thin sheet, wherein the repeatedly contacting the surface of the thin sheet forms a respective hole in the thin sheet corresponding to each respective needle of the needle array, wherein the repeatedly contacting the surface of the thin sheet comprises contacting the thin sheet with the plurality of needles of the needle array without rotating the plurality of needles about the longitudinal axis, without rotating the plurality of needles with respect to the thin sheet, and without use of a slurry or a cooling fluid;
translating the needle array such that the needle array is positioned above a second region of the thin sheet; and
repeatedly contacting the surface of the thin sheet within the second region with the needle array at an operating frequency of above 20 kHz for a period of time sufficient to form a second plurality of holes in the second region of the thin sheet, wherein the repeatedly contacting the surface of the thin sheet forms a respective hole in the thin sheet corresponding to each respective needle of the needle array, wherein the repeatedly contacting the surface of the thin sheet comprises contacting the thin sheet with the plurality of needles of the needle array without rotating the plurality of needles about the longitudinal axis, without rotating the plurality of needles with respect to the thin sheet, and without use of the slurry or the cooling fluid.