| 摘要 |
<p>1,037,711. Electrically heated drums. REYNOLDS METALS CO. Feb. 4, 1964 [Feb. 8, 1963], No. 4758/64. Heading H5H. [Also in Division B5] A spiked roller for use in perforating thermoplastic material (see Heading B5A) is internally heated by three electrical elements 26, Figs. 3 and 4 (not shown), each of which is connected at one end to a bus bar 33 and at the other end to one of three slip-rings 34 which contact commutator brushes thus connecting the elements to a conventional three-phase supply. The resistance of each element is increased towards its ends to increase its heat output and thus counteract any cooling of the roll at its ends.</p> |
