Packing rings

Claim 1

A segmented packing ring comprising the combination of three identical arcuate segments arranged and positioned to form inner and outer circumferences with top and bottom surfaces in a common plane, each arcuate segment having a body portion and a face seal portion rigidly connected thereto; each face seal portion being arranged to extend beyond one end of the body portion to which it is connected and to overlap one end of the body portion of an adjacent arcuate segment; each of said face seal portions being arranged to slideably engage a face seal portion of an adjacent arcuate segment as contiguous surfaces along a line parallel to a tangent to the inner circumference of said packing ring with the face seal contiguous surfaces along said line of slideable engagement being substantially perpendicular to the plane of said packing ring with an end gap at said inner circumference extending only part of the ring width towards said outer circumference; the adjacent end of said body portions being spaced from each other by gaps and arranged to extend beyond one end of said face seal portion, each arcuate segment inner arcuate surface having a pressure balancing groove therein substantially in the plane of said packing ring; and spring means provided on each arcuate segment for urging the three arcuate segments radially inward toward a common center.