Patent Number: 8,821,081

Title: Tool for repairing cross-threading and other damage in threaded blind holes

Abstract: A slotted inverse tap, compressible for insertion past damaged entry threads in blind holes. (FIG. 1 thru FIG. 5) The tool can be made to smaller sizes than that of prior art. An elongate slot (23) proceeds through a first threaded end (21), then well into a reduced diameter cylindrical body (25). After insertion to the hole bottom, a tabbed shim (28) is inserted to the slot from its side, then pressed down until stopped. The shim (28) enforces mating engagement with undamaged internal threads. A second end of hex and/or squared or other configuration facilitates use of a tap wrench or other tool for rotational extraction. Damaged threads are reformed/re-cut upon rotational withdrawal.

Inventors: Foss; Vernon L. (Brooklyn Park, MN)


International Classification: B23G 5/08 (20060101)

Expiration Date: 9/02/12018