the automobile industry another case of application of the exchanging apparatus described here is the manufacture of cable e g low or even medium voltage cable the head 3 is supported by a first movable assembly 4 which need not be described in detail here but which can carry out a rotational movement about an axis defined by the pivot 5 a jack 6 permits controlling these rotational movements which then communicate to the head 2 a circular translatory motion permitting it to be brought into a position symmetrical to that of a head 7 which for its part is in preparation position in fig1 the head 7 is associated with a second movable assembly 4 symmetrical with the assembly 4 of the first one and carrying out the same movements in the opposite direction arrows b indicate the circular translatory movements of the heads 2 and 7 a base 8 common to the movable assemblies 4 further bears a connection unit 9 with which a locking clamp 10 is associated indeed as is seen in the lower right hand part of fig1 each extrusion head used with the exchanging apparatus described comprises a connection part 11 which is rigidly fixed against one of its faces perpendicular to the axis of the pivoting movement of the movable assemblies 4 a plane surface 12 of the connection part 11 is in contact with a homologous plane surface of a connection part 13 which is fixed and integral with the connection unit 9 when the movement of a movable assembly has brought the extrusion head borne by this assembly into the working position the locking clamp 10 is actuated so that the two homologous connection parts 13 and 11 which face one.