A device for cold working a pipe element , said device comprising: a housing ; a plurality of gears mounted within said housing , each one of said gears being rotatable about a respective one of a plurality of axes of rotation , said axes of rotation being parallel to one another, said gears being positioned about a central space for receiving said pipe element ; a plurality of cam bodies , each said cam body mounted on a respective one of said gears ; a plurality of cam surfaces extending around each said cam body , each said cam surface being engageable with said pipe element received within said central space and comprising a region of increasing radius , said radii being measured about and from one of said axes of rotation , all of said cam surfaces on each said cam body being circumferentially aligned with one another; a respective discontinuity of said cam surfaces being positioned between each of said cam surfaces on each said cam body ; characterized in that , at least one stop surface projecting from one of said cam bodies transversely to said axes of rotation of said one cam body , said at least one stop surface being positioned adjacent to a discontinuity of said one cam surface ; a pinion mounted within said central space within said housing , said pinion meshing with said plurality of gears and being rotatable about a pinion axis oriented parallel to said axes of rotation ; a cup adjacent said pinion , said cup receiving said pipe element upon insertion of said pipe element into said central space ; wherein said cup is movable relatively to said housing along said pinion axis between a first position, wherein said cup engages said at least one stop surface thereby preventing continuous rotation of said cam bodies , and a second position, wherein said cup is out of engagement with said at least one stop surface , thereby permitting continuous rotation of said cam bodies . a housing ; a plurality of gears mounted within said housing , each one of said gears being rotatable about a respective one of a plurality of axes of rotation , said axes of rotation being parallel to one another, said gears being positioned about a central space for receiving said pipe element ; a plurality of cam bodies , each said cam body mounted on a respective one of said gears ; a plurality of cam surfaces extending around each said cam body , each said cam surface being engageable with said pipe element received within said central space and comprising a region of increasing radius , said radii being measured about and from one of said axes of rotation , all of said cam surfaces on each said cam body being circumferentially aligned with one another; a respective discontinuity of said cam surfaces being positioned between each of said cam surfaces on each said cam body ; at least one stop surface projecting from one of said cam bodies transversely to said axes of rotation of said one cam body , said at least one stop surface being positioned adjacent to a discontinuity of said one cam surface ; a pinion mounted within said central space within said housing , said pinion meshing with said plurality of gears and being rotatable about a pinion axis oriented parallel to said axes of rotation ; a cup adjacent said pinion , said cup receiving said pipe element upon insertion of said pipe element into said central space ; wherein said cup is movable relatively to said housing along said pinion axis between a first position, wherein said cup engages said at least one stop surface thereby preventing continuous rotation of said cam bodies , and a second position, wherein said cup is out of engagement with said at least one stop surface , thereby permitting continuous rotation of said cam bodies . <EOS>