Apparatus for aligning ends of wire conductors extending from coil members inserted in slots of a core of a dynamo electric machine to join a plurality of ends (EP1, EP2, EP3, EP4, EP5) of at least two wire conductors, in particular by means of a welding operation; wherein said ends (EP1, EP2, EP3, EP4, EP5) to be joined are intended to be aligned along radiuses (R1, R2) of said core , and wherein a spacing (S1, S2) exists between two adjacent radiuses (R1,R2) of said core ; said apparatus comprising at least one first alignment unit having: - a first member configured for being positioned in a first spacing (S1) existing on one side of a first radius (R1) of the core; - a first abutment portion configured for being positioned at a first position situated radially between a first group of ends (EP1) to be joined and a second group of ends (EP2) to be joined, said first and second group of ends being intended to be aligned along said first radius (R1); - a second member configured for being positioned in a second spacing (S2) existing on the opposite side of said first radius (R1); - a second abutment portion configured for being positioned at a second position situated radially between said first group of ends (EP1) to be joined and said second group of ends (EP2) to be joined; - a first pusher situated at a radially outer position relative to said core and configured for pushing said first group of ends (EP1) to be joined against said first abutment portion ; - a second pusher situated at a radially inner position relative to said core and configured for pushing said second group of ends (EP2) to be joined against said second abutment portion ; - first means configured for relatively moving said first member , said second member , said first abutment portion and said second abutment portion in an axial direction (Z, Z') of said core ; - second means configured for relatively moving said first radial pusher and said second radial pusher in the radial direction (R, R') of said core ; and - third means configured for moving said first member and said second member one towards the other in the circumferential direction (CS, CS')of said core. - a first member configured for being positioned in a first spacing (S1) existing on one side of a first radius (R1) of the core; - a first abutment portion configured for being positioned at a first position situated radially between a first group of ends (EP1) to be joined and a second group of ends (EP2) to be joined, said first and second group of ends being intended to be aligned along said first radius (R1); - a second member configured for being positioned in a second spacing (S2) existing on the opposite side of said first radius (R1); - a second abutment portion configured for being positioned at a second position situated radially between said first group of ends (EP1) to be joined and said second group of ends (EP2) to be joined; - a first pusher situated at a radially outer position relative to said core and configured for pushing said first group of ends (EP1) to be joined against said first abutment portion ; - a second pusher situated at a radially inner position relative to said core and configured for pushing said second group of ends (EP2) to be joined against said second abutment portion ; - first means configured for relatively moving said first member , said second member , said first abutment portion and said second abutment portion in an axial direction (Z, Z') of said core ; - second means configured for relatively moving said first radial pusher and said second radial pusher in the radial direction (R, R') of said core ; and - third means configured for moving said first member and said second member one towards the other in the circumferential direction (CS, CS')of said core. <EOS>