CONTACT PIECE, METHOD AND TOOL FOR ITS MANUFACTURE Russian patent published in 2011 - IPC H01H1/21 

FIELD: electricity.

SUBSTANCE: contact piece is made from composite material in the form of body of rotation, which is restricted with side surface with generatrix consisting of straight-line and (or) curved sections and two parallel surfaces of bases, made from fine dense graphite with specific resistance of not more than 16.0 mcOhm*m, compression strength of not less than 60 MPa, ash content of not more than 0.3% and volume porosity of not more than 20%. Manufacturing method of contact piece consists in the fact that flat workpiece is made from fine dense graphite, which has thickness equal to height of contact piece; workpiece is installed into the device, part of contact piece is cut out on one side, and workpiece is reinstalled and the rest part of contact piece is cut out on the other side. Contact piece manufacturing tool includes shank and working part consisting at least of one cutting element offset relative to rotation axis of tool the cutting edges of which form side furnace of contact piece.

EFFECT: improvement of contact piece manufacturing accuracy, stabilisation of transient resistance of contact pair, and elimination of contacts welding.

5 cl, 3 dwg, 1 tbl