Abstract: A cover for closing a top opening of a thermite reaction chamber of a crucible is substantially continuous and is secured to an annular filter lining via a bottom peripheral edge for making contact on a top peripheral edge of the crucible. The filter lining is substantially continuous and is suitable for constituting a substantially continuous contact medium between the bottom edge and top edge. The cover is applicable, for example, to thermite welding, e.g., for use in tunnels or underground.

Abstract: This present invention concerns a mould for the aluminothermic welding of railway rails. The compressible lining (58) used to seal the moulding die in relation to leakages of the weld metal in the liquid state is limited to the parts of the contact surfaces (52) of the parts (19) of the mould on the rails to be welded, corresponding to the bottom, the sides and the top of the foot, to the sides of the web and below the head. The rigid refractory material of the parts (19) is exposed in the parts (67, 71) of the contact surfaces corresponding to the sides and the top of the head, and suitable to be removed selectively from the latter. This makes it easy to adapt the mould to rails with different degrees of wear.

Abstract: A cover for closing a top opening of a thermite reaction chamber of a crucible is substantially continuous and is secured to an annular filter lining via a bottom peripheral edge for making contact on a top peripheral edge of the crucible. The filter lining is substantially continuous and is suitable for constituting a substantially continuous contact medium between the bottom edge and top edge. The cover is applicable, for example, to thermite welding, e.g., for use in tunnels or underground.