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:
Sep. 23, 1986
Filed:
Aug. 29, 1985
William P Gundy, Amherst, NH (US);
NPC Systems, Inc., Milford, NH (US);
Abstract
A low cost apparatus and method for centering a grinding and cutting apparatus on the face of the spigot or a bell of a reinforced or non-reinforced concrete pipe, manhole riser, or the like. It is mechanical to avoid the expense and uncertainty of hydraulic sensing systems. The four contact guides, one in each quadrant, are each mounted at the lower portion of one of four guide arms, each centrally pivoted to the rotatable support of the machine and each having an upper portion above the pivot connected by an elongated link to one of a pair of rotatable pivot plates. Hydraulic pistons and cylinders maintain a yieldable resistance to turning of the pivot plates. As the base plate of the grinding and cutting apparatus approaches the face of the spigot, with the centering guides extended therebelow, the guides contact the top edge of the pipe or spigot and are forced open relative to each other while forcing the base plate into exact centered position, based on the configuration of the exterior face of the spigot.