GB731044A - Improvements in or relating to high frequency coil systems comprising a slidable electrically conductive core - Google Patents

Abstract

731,044. Inductors. PHILIPS ELECTRICAL INDUSTRIES, Ltd. Oct. 22, 1953 [Oct. 25, 1952], No. 29208/53. Class 38 (2). [Also in Group XL (c)] A high-frequency coil system comprises at least one coil the inductance of which is varied by a slidable electrically conductive non- magnetic core which comprises at least two telescoping parts which parts are most fully telescoped at least when the core is totally without the coil. A coil 3 wound from a tubular copper conductor is provided with a slidable copper core 23 which comprises two telescoping parts 37, 39. The part 37 is fixed to a bracket 35 which is caused to slide along guide rails such as 13 and the part 39 is spaced from the part 37 by a spring 47. A pin 49 secured to the part 39. has a control card 51 attached thereto which is led over pulleys 53, 55 and finally secured to a fixed member 57. Move. ment of a control knob causes the bracket 35 to move to the right, thus moving the core part 37 out of the coil 3. At the same time the core part 39 will also move to the right due to its attachment to the cord 51 but since the cord is led through an angular change of direction of 180 degrees the core part 39 will move at twice the rate of the core part 37. Thus when the part 37 is clear of the coil the part 39 will be fully telescoped therewith. In another embodiment both parts initially move at the same rate until one part is clear of the coil, which part then stops whilst the other part continues to move, telescoping the stopped part. In yet another embodiment initially only one part moves to telescope the other and when fully telescoped both parts move together to clear the coil.