Abstract: A method for inspecting a cold expanded fastener hole in a structural part to confirm that the hole has been expanded by a desired amount involves determining the degree to which the hole has been expanded as a function of the out-of-plane deformation in material surrounding an entrance or exit of the hole formed as a result of the cold expansion process. Out-of-plane deformation at either of the entrance or exit is compared to a model constructed from an array of experimentally or analytically determined out-of-plane deformation profiles for a hole with the same, or substantially the same, dimensions subjected to varying degrees of cold expansion. The degree of expansion of the hole is derived based on this comparison.
Type:
Grant
Filed:
December 16, 1994
Date of Patent:
January 2, 1996
Assignee:
Northrop Grumman Corporation
Inventors:
Alan Levy, James R. Kennedy, John M. Papazian
Abstract: Instrumentation and techniques to image small objects, such as but not limited to individual human chromosomes, with nanometer resolution, to cut-off identified parts of such objects, to move around and manipulate such cut-off parts on the substrate on which they are being imaged to predetermined locations on the substrate, and to remove the cut-off parts from the substrate. This is accomplished using an atomic force microscope (AFM) and by modification of the conventional cantilever stylus assembly of an AFM, such that plural cantilevers are used with either sharp-tips or knife-edges thereon. In addition, the invention can be utilized for measuring hardness of materials.
Type:
Grant
Filed:
March 23, 1993
Date of Patent:
October 31, 1995
Assignee:
Regents of the University of California
Inventors:
Robert J. Tench, Wigbert J. Siekhaus, Mehdi Balooch, Rodney L. Balhorn, Michael J. Allen
Abstract: A test system for a piezoelectric element per se or a piezoelectric element in a physical system, which is subject to forces which deform the piezoelectric element, couples an electrical pulse to the piezoelectric element sufficient to stress the element and induce mechanical ringing upon pulse removal. The ringing electrical signal developed by the piezoelectric element characterizes the functionality of the piezoelectric element. A response circuit which is responsive to the ringing electrical signal provides an electrical signal indicative of the functional condition of the piezoelectric element. The electrical signal is peak detected. The peak detected voltage is compared with a reference voltage to provide an indication of the functionality of the piezoelectric element.
Abstract: Misfiring in an engine cylinder can be detected based on the pressure therein as sensed by a pressure sensor with a high degree of reliability at any time even if the output signal of the pressure sensor contains an offset component superposed on a pressure component representative of the actual cylinder pressure. In one form, the pressure sensor output is differentiated to eliminate the influence of the offset component and then processed to generate a power stroke pressure information signal in the form of the time of a pressure-change peak in the differentiated pressure sensor output or an integrated value of the differentiated output, which is then compared with a threshold so as to determine whether misfiring took place in the cylinder.