referring more particularly to the drawings , a godet which embodies the present invention is shown in fig1 at 1 . the godet 1 comprises a bell - shaped casing 2 which is composed of a tubular outer wall 3 and a front wall 4 which closes the casing 2 at its end having the larger diameter . the front wall 4 is provided with a hub , which has a bore adapted to the tapering free end of a godet shaft 13 . by means of a threaded nut 16 , the front wall 4 is releasably secured to godet shaft 13 , with the front wall 4 extending radially from the axis of the shaft . the shaft 13 is mounted in cantilever fashion to the support member 14 of the machine frame so as to permit the shaft 13 to rotate about its axis , and the shaft 13 defines a free end to which the front wall 4 of the casing is attached as described above . a cylindrical sleeve 15 is fixed to the support member 14 so as to coaxially surround the shaft an induction heating means is mounted on the sleeve 15 . more particularly , the induction heating means includes a tubular ferromagnetic core , which may be in the form of a lamella assembly , and which includes a cylindrical wall portion 12 which is disposed coaxially upon the sleeve 15 . the core further includes a plurality of axially spaced apart annular ribs 8 , 9 , 10 which extend radially outwardly from the wall portion 12 . the ribs 8 , 9 , 10 have ends which terminate at a common radial distance from the axis of the shaft 13 , and which terminate on a common imaginary circular cylindrical contour surface 17 . the core also has an outer end rib adjacent the free end of the shaft 13 , and an inner end rib 29b adjacent the support member 14 . the end ribs 29a , 29b have the same diameter as the ribs 8 - 10 , and they all extend to and terminate on the imaginary cylindrical contour surface 17 . an induction coil 11 is positioned upon the cylindrical wall portion 12 of the core between each adjacent pair of the ribs 8 - 10 , 29a , 29b . all ribs 8 - 10 , 29a and 29b extend radially beyond the outer circumference of induction coils 11 . also , it is possible to have the end rib 29b which abuts the support member 14 to extend with a slight play up to the inside surface of the outer wall of the casing at end 3a . arranged in the inside surface of the front wall 4 of the godet which faces inwardly toward the support member 14 , is an annular recess 33 . the annular recess 33 includes a flat base surface which is parallel to the inside surface of the front wall , and an outer cylindrical surface which is concentric to the axis of the shaft 13 and lies on an imaginary cylindrical boundary surface 18 as hereinafter further described . also , the end rib 29a of the core is received within the annular recess 33 , with a radial play or gap 20 as well as an axial spacing 22 , which acts to impede the magnetic flux in the axial direction . the axial spacing 22 is preferably larger than the radial spacing of the gap 20 . in the embodiment shown in fig1 radially inwardly directed ribs 5 - 7 also extend from the inner surface 19 of the outer wall 3 of the casing 2 . in the longitudinal sectional view of fig1 the ribs 5 - 7 face intermediate ribs 8 - 10 extending from the core 12 , whereas end rib 29a is received into the aforesaid annular recess 33 of the front wall 4 and has there its path for the magnetic flux . as aforesaid , end rib 29b adjacent the support member 14 may extend directly to the inner surface of the outer wall at 3a . the ribs 5 - 7 proceeding from the inner surface 19 of the outer wall of the casing extend to and terminate on a common imaginary circular cylindrical boundary surface 18 . the boundary surface 18 is coaxial with the contour surface 17 , and the radius of the boundary surface 18 is larger by the thickness of the magnetic gap 20 provided between the ribs facing one another than the radius of the contour surface 17 . opposite ribs 5 - 8 , 6 - 9 , 7 - 10 preferably each have the same wall thickness and are radially aligned with one another such that they each abut associated radial planes 30 - 32 of the godet 1 . when the wall thickness of the inner and outer ribs differs , the godet casing 2 is arranged with respect to the ferromagnetic core such that the ribs face one another with their centers aligned . at each of its ends , the surface of the outer wall 3 of the godet 1 has a cylindrical yarn inlet region 3a and a cylindrical yarn outlet region between which a conical yarn - bearing surface extends . in the illustrated embodiment , the yarn - bearing surface is smooth with a straight line as surface line , however , as is known per se , it may be stepped or have a grip - improving terracing of very fine gradation , if need arises . in the embodiment of fig1 the connection of the casing 2 with the godet shaft 13 is provided by a threaded nut 16 , which is threaded onto a bolt provided on the free end of godet shaft 13 . the nut may be provided with a corresponding locking mechanism ( not shown ). in some applications , the connection as illustrated in fig1 has turned out to be insecure , and for reasons of safety , the connection as shown in fig2 may be preferred . in this embodiment , a threaded bore 23 extending along the shaft axis is provided in godet shaft 13 from its free end , which receives a necked - down bolt 24 consisting of a threaded portion 25 and a neck 26 , preferably by applying a determined torque . such connections have been found to be lasting and reliable , in particular when used in heated godets . they also have the advantage of a simpler assembly , since during the assembly the godet casing 2 need not be heated to the operating temperatures of godet 1 . to run signal lines which are intended for monitoring the temperature ranges of outer wall 3 , it is preferred , as shown in fig2 to provide a signal line conduit 27 along the axis of the godet shaft which continues in the embodiment of fig2 through the necked - down bolt 24 . for this reason , the latter is preferably hollow over its entire length and provided with an axial channel as noted above , the casing 2 preferably consists of a ferromagnetic material , and as illustrated in fig1 - 3 of the drawings , the outer wall 3 and the front wall 4 are of integral one - piece construction . however , as illustrated in fig4 the front wall may be a separate piece 4a which is joined to the outer wall 3 , and the front wall may comprise two layers , with the inner layer 38 consisting of a ferromagnetic material and having substantially the same thickness as the outer end rib 29a . shown in fig3 is an embodiment of the godet i which is slightly modified from that of fig1 . like numerals are used to the extent that the structural elements are comparable . in particular , the godet i of fig3 is provided substantially over the entire inner surface of the outer wall 3 , namely in all regions between radial outer ribs 5 - 7 and 29a - b , with radial short - circuit rings 34 - 37 of an electrically highly conductive metal , such as for example copper , brass or the like . these rings effect an even heating of godet casing 2 to the intended temperature . the short - circuit rings 34 - 37 on the inner surface of the outer wall 3 may be made , for example , by a suitable centrifugal casting method . the embodiment of the godet as shown in fig3 further shows at the end of cylindrical region 3a of godet casing 2 the presence of a short radial rib which has an end lying on the imaginary surface 18 . also , in the region of the front wall 4 at the godet end with the larger diameter , there is provided a substantially enlarged axial gap 22 between the axial front end surface 21 of the radial rib 29a of the core and the base surface of the annular recess 33 in the front wall 4 of the godet . this enlarged axial gap 22 is preferred , so as to impede the magnetic flux into the front wall of the godet and corresponding energy losses as a result of axial heat radiation . finally , it should be noted that it is possible to further modify the godet within the scope of the present invention . in particular , it is possible to terrace or step the outer yarn - bearing wall 3 in more or less fine increments , as is known per se from u . s . pat . no . 4 , 891 , 872 , and as illustrated in fig4 . likewise , the free end of godet 1 may be closed by a cover ( not shown ) attached to the front wall 4 of the godet , so as to avoid having yarn residues adhere to the threaded connection ( i . e ., the thread , nut 16 , head 24 of necked - down bolt 26 ), or that the operating personnel are endangered . in the drawings and specifications , there has been set forth a preferred embodiment of the invention , and although specific terms are employed , they are used in generic and descriptive sense only and not for purpose of limitation .