GB 1250744 A
1,250,744. Internally heated hollow roller. DIENES-HONEYWELL HOLDING G.m.b.H. 18 March, 1970 [20 March, 1969], No. 12933/70. Heading B5B. [Also in Division F2] In the embodiment shown in Fig. 1, an internally heated rotatable hollow roller or godet such as may be used for forwarding and heating yarn looped around it and which is provided with a temperature sensor includes a hollow metal roller 1 the hub 2 of which is fixed on to a shaft 3 which is, in turn, rotatably supported by a stationary structure 4 and is coupled to a driving means (not shown). A stationary induction heating coil 5 is mounted inside the roller 1 in a known manner. Alternative heating means, such as electrical resistance heating means, may be used. Fixed to the structure 4 is a flange 6 which, with the cover ring 9 secured about its periphery, constitutes a thermal insulating body preferably made of a poor heat-conducting material such as a ceramics material. The flange 6 near its periphery supports at least one temperature sensor 7, such as a resistance bulb, which is positioned in adjacent radial spaced relation to a portion 8 of the peripheral surface of roller 1. The cover ring 9 is provided with a mirror-like inner surface 12 for reflecting heat radiated from surface portion 8. The cover ring 9 may be integral with the flange 6. The cover ring 9 defines an annular recess 13 with the surface portion 8 and with an annular projection 11 which extends around the peripheral surface of roller 1. The projection 11 distinguishes the surface portion 8 from the greater portion of the peripheral surface of roller 1, and defines one of the four walls of the recess 13 and also defines a clearance 14 with cover ring 9. In a second illustrated embodiment the cover ring 9 is an integral part of a cup-shaped portion of the support structure 4 and extends over the end of the roller 1 facing this structure, whereby the electric connections to the temperature sensor are enclosed and protected. In a third illustrated embodiment of the apparatus of the invention the annular projection 11 of the roller 1 has a greater radial extension than as shown in Fig. 1 and has two axially extended stepped shoulders which overlap a complementary stepped portion at the end face of the cover ring 9 and the outer surface, respectively, of the free end of the cover ring. Entry of the yarn being heated into the recess 13 via the clearance 14, in operation of the roller is thereby prevented.