Joint arrangements

Claim 2

A joint arrangement comprising first and second substantially co-axial metal parts of annular cross-section and provided with substantially co-axial surfaces of revolution, the said surfaces having straight generating lines which are mutually inclined, and a ceramic part of annular cross section and provided with a pair of surfaces of revolution having straight generating lines whose inclinations to their common axis are respectively substantially equal to the inclinations to the associated axis of the generating lines of said surfaces on said metal parts, means securing said metal parts together so as to permit, during thermal expansion, relative movement between their surfaces of revolution and so as to engage by clamping action the corresponding surfaces on the ceramic part, the arrangement being such that points on the said surfaces of the metal parts move, during thermal expansion, along paths which define the generating lines of the corresponding surfaces.

Claim 3

The joint arrangement as claimed in claim 1 in which each of the surfaces of revolution on said metal parts has a free end between which ends the ceramic part extends, in which the metal parts are secured together at a location spaced from the said free ends and in which the axial dimension of one of the parts between the said location and the free end of thesaid one part is greater than the corresponding dimension on the other of the parts.

Claim 4

The joint arrangement as claimed in claim 1 in which each of the surfaces of revolution on said metal parts has a free end, between which ends the ceramic part extends, and in which the radius of the free end of one of the parts is greater than the radius of the free end of the other of the parts.

Claim 5

The joint arrangement as claimed in claim 2 in which the surfaces of revolution diverge towards the said free ends.

Claim 6

The joint arrangement as claimed in claim 2 in which the surfaces of revolution converge towards the said free ends.

Claim 7

The joint arrangement as claimed in claim 2 in which the included angles of the surfaces of revolution, are substantially equal.

Claim 8

The joint arrangement as claimed in claim 1 in which layers of resilient packing material are interposed between adjacent surfaces of revolution.

Claim 9

In a joint arrangement between a metal tube having an external annular flange and a ceramic tube having an external annular flange and a metal ring cooperable with the flanges of the tubes for securing the tubes together, said metal tube having a co-axial frusto-conical surface, said metal ring having an inwardly directed lip defining a frusto-conical surface, the included angle of the frusto-conical surface of the metal tube being less than that of the frusto-conical surface of the metal ring, the flange of the ceramic tube having first and second co-axial frusto-conical surfaces, the included angles of the frusto-conical surfaces of the flange of the ceramic tube being respectively equal to the included angles of the frusto-conical surfaces of the metal tube and metal ring, the first and second frusto-conical surfaces of the ceramic tube engaging the frusto-conical surfaces of the metal tube and metal ring respectively, and the axial dimension of the metal tube within the metal ring being less than the axial dimension of the ring itself, the arrangement being such that, during thermal expansion, the frusto-conical surface of the metal ring moves away from the frusto-conical surface of the metal tube thereby maintaining a clamping action on the flange of the ceramic tube and at the same time applying no stress to the ceramic tube as a result of thermaL expansion.

Claim 10

In a joint arrangement between a metal tube having an external annular flange and a ceramic tube having an external annular flange and a metal ring cooperable with the flanges of the tubes for securing the tubes together, said metal tube having a co-axial frusto-conical surface, said metal ring having an inwardly directed lip defining a frusto-conical surface, the included angle of the frusto-conical surface of the metal tube being less than that of the frusto-conical surface of the metal ring, the flange of the ceramic tube having first and second co-axial frusto-conical surfaces, the included angles of the frusto-conical surfaces of the flange of the ceramic tube being respectively equal to the included angles of the frusto-conical surfaces of the metal tube and metal ring, the first and second frusto-conical surfaces of the ceramic tube engaging the frusto-conical surfaces of the metal tube and metal ring respectively, and the axial dimension of the metal tube within the metal ring being less than the axial dimension of the ring itself, the arrangement being such that, during thermal expansion, the frusto-conical surface of the metal ring moves away from the frusto-conical surface of the metal tube thereby maintaining a clamping action on the flange of the ceramic tube and at the same time applying no stress to the ceramic tube as a result of thermaL expansion.