Contact bodies and method and apparatus of making same

A contact body comprising at least a first and second pair of corrugated contact sheets having crests and valleys, the crests having peak surfaces and the valleys having trough surfaces, each contact sheet having opposing surfaces and a plurality of projections extending outward from one surface and located on the peak surfaces of the crests and the trough surfaces of the valleys, the projections extending in the same direction from the one surface of each contact sheet, wherein each projection defines a depression on the opposite surface of the contact sheet, the projections of one contact sheet being disposed within mating depressions of an adjacent contact sheet to form projection-depression couplings, that are mechanically deformed to form a plurality of positive locks in the form of flattened interlocking rivets, some of the plurality of projections being edge projections on each peak surface and each trough surface adjacent side edges of each sheet, and the rest of the plurality of projections being interior projections on each peak surface and each trough surface in the interior of the sheet away from the side edges, the edge projections and the interior projections of the two contact sheets of each of the first and second pair forming projection-depression couplings with corresponding projections of the adjacent sheet of the pair, at least some of the projection-depression couplings comprised of the edge projections and the interior projections of each contact sheet of the first and second pair being mechanically deformed to form positive locks between at least some of the projections of contact sheets of the pair, wherein at least some of only the edge projections of the first pair of contact sheets that form projection-depression couplings with the edge projections of the second pair of contact sheets are mechanically deformed to form positive locks in the form of flattened interlocking rivets between the first and second pairs of contact sheets.