The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 15, 1987
Filed:
Aug. 27, 1986
Durham S McCauley, Boston, NY (US);
Jeffrey R Sullivan, Boston, NY (US);
McGard, Inc., Buffalo, NY (US);
Abstract
A pipe plug which cannot be removed from a pipe with the same key with which it is installed, the pipe plug having a body with a plurality of arcuate grooves having inclined arcuate ramps leading from its face into its body and terminating at shoulders for abutting engagement with first key having pins which bear against the shoulders to tighten the plug in the pipe but which cannot loosen the plug because the pins will ride up the ramps and cam out of engagement with the plug, and a second key for removing the plug including a ridge on the second key for mating with a complementary curvilinear groove in the plug. A counterbore is provided in the face of the plug to receive portions of the ridge which are of substantially the same diameter as the counterbore to thereby center the second key with respect to the plug and guide it while the second key is rotated until the ridge thereon falls into the groove to effect mating engagement therewith.