Patent ID: 7641168

Claim:
A mould for the aluminothermic welding of railway rails ( 2 ) that are aligned with each other longitudinally, of the type that includes several parts ( 19 , 22 ) in rigid refractory material, that is suitable to be assembled temporarily around transverse end-pieces ( 3 ) of rail ( 2 ) to be welded, which together form: a moulding die ( 25 ), open upwards, arranged to receive poured welding metal in the liquid state, and enveloping the two end-pieces ( 3 ), a space( 4 ) created between them, and a first zone ( 24 ) of each rail ( 2 ), immediately adjacent to the corresponding end-piece ( 3 ), in order to communicate a given shape to the weld metal as its solidifies, two continuous surfaces ( 60 , 63 to 68 , 71 ) arranged to make contact with a second zone ( 26 ) of each rail ( 2 ) immediately adjacent to the first zone ( 24 ) of the latter, opposite to the corresponding end-piece ( 3 ) in relation to this first zone ( 24 ), and carrying an attached compressible lining ( 58 , 59 ) in order create a contact seal in relation to the weld metal in the liquid state, characterised in that the said compressible lining ( 58 , 59 ) is limited to the parts ( 60 , 63 , 64 , 65 , 66 ) of each contact surface corresponding to the bottom ( 9 ), the sides ( 10 ) and the top ( 11 ) of a foot ( 8 ) of the corresponding rail ( 2 ), to the sides ( 13 ) of a web ( 12 ) of the corresponding rail ( 2 ) and to the bottom ( 15 ) of a head ( 14 ) of the corresponding rail ( 2 ), in that the said rigid refractory material is directly exposed in parts ( 67 , 68 , 71 ) of each contact surface corresponding to the sides ( 17 ) and to the top ( 16 ) of the head ( 14 ) of the corresponding rail ( 2 ), in that each contact surface presents, between its part ( 68 , 71 ) corresponding to the top ( 16 ) of the head ( 14 ) of the corresponding rail ( 2 ) and the said compressible lining ( 58 ) of its part ( 66 ) corresponding to the bottom ( 15 ) of the head ( 14 ) of the corresponding rail ( 2 ), at the maximum compressed state with reference to the normal conditions of use, a spacing which is less than the spacing (h) between the top ( 16 ) and the bottom ( 15 ) of the head of a new rail ( 2 ), and in that the said rigid refractory material is chosen or treated in order to facilitate its selective removal at least in the parts ( 68 , 71 ) of each contact surface corresponding to the top ( 16 ) of the head ( 14 ) of the corresponding rail ( 2 ) and thus to allow adaptation of the mould ( 6 ) to the rails ( 2 ) whose head ( 14 ) is worn, with continuous contact of the said contact surface ( 60 , 63 to 68 , 71 ) at the bottom ( 9 ), the sides ( 10 ) and the top ( 11 ) of the foot ( 8 ) of the two rails ( 2 ), at the sides ( 13 ) of the web ( 12 ) of the two rails ( 2 ) and at the bottom ( 15 ), the sides ( 17 ) and the top ( 16 ) of the head ( 14 ) of the two rails ( 2 ).