Abstract A device strips circular areas of insulation to expose the flat conductors in flexible printed circuits, flat electrical cables, multilayer circuit boards and the like, to permit making electrical connections thereto. The basic principle of operation resembles that of an end mill or drilling machine. The new machine employs rotating cutters of novel shape which cut more readily through insulating films and sheets than through metals such as copper, and the machine has a precision depth stop. Both features prevent cutting through the thin foil conductors. The depth stop may be set so that the cutter penetrates the foil by a small fraction of its thickness, exposing a clean metal surface for soldering. The bottom of the cut is visible during the cutting operation.
An insulation stripping device for a flat circuit having metal foil conductors laminated between relatively thin insulating film layers, comprising: a rotatable cutter having a cylindrical body and a tapered end portion; straight cutting edges perpendicular to its axis of rotation at the tip of said end portion; said straight cutting edges forming at least one substantially continuous cutting edge along the entire length thereof, the leading boundary planes of said edges having a relatively small angle of negative rake; means to rotate said cutter; means to advance said cutter axially into said flat circuit; and sensitive means to precisely control the depth of penetration of said cutter, whereby said device is able to remove several thousandths of an inch of said film in increments of less than .001 of an inch without cutting through said foil.
Claim 2
Dependent Claim
137 words
An insulation stripping device for a flat circuit having metal foil conductors laminated between relatively thin insulating film layers, comprising: a rotatable cutter having a cylindrical body and a tapered end portion; straight cutting edges perpendicular to its axis of rotation at the tip of said end portion; said straight cutting edges forming at least one substantially continuous cutting edge along the entire length thereof, the leading boundary planes of said edges having a relatively small angle of negative rake; means to rotate said cutter; means to advance said cutter axially into said flat circuit; and sensitive means to precisely control the depth of penetration of said cutter, whereby said device is able to remove several thousandths of an inch of said film in increments of less than .001 of an inch without cutting through said foil.
Claim 3
Dependent Claim
41 words
An insulation stripping device as in claim 1, wherein: said end portion is bounded on opposite sides by two plane surfaces each inclined toward the axis of said body at a relatively small angle; and said angle constituting said negative rake.
Claim 4
Dependent Claim
34 words
An insulation stripping device as in claim 2, wherein: said plane surfaces intersect a pair of tip surfaces; and said tip surfaces being inclined from the normal to said axis to provide clearance angles.
Claim 5
Dependent Claim
30 words
An insulation stripping device as in claim 3, wherein: said tip surfaces are relatively narrow; and whereby the area swept by said cutting edges is visible during the cutting operation.