GB237742A - Improvements in or relating to variable condensers for use in wireless systems - Google Patents

Abstract

237,742. Mitchell, G. A. Aug. 28, 1924. Condensers comprise, in combination, a knob, dial, or equivalent adapted for attachment to a variable condenser, a vernier and means for adjusting the same in such a manner as to form a single detachable unit, capable of being easily applied to any existing condenser not having a vernier. Preferably the vernier comprises a fixed and a movable plate or plates. In Figs. 1 and 2, the vernier comprises a fixed and a movable plate 1, 2, the fixed plate 1 being secured to the dial 4 by screws and having a hole 6 to admit the spindle 7 of the main condenser. The movable plate 2 fits rotatably over the spindle and is separated by a washer 10 from the plate 1 and, if necessary, by a washer 11 from the dial 4. Operation is effected by a knob 13 working in an arcuate slot 14 in the dial, the knob being long enough to obviate hand capacity effects. The movable plate engages the spindle 7 for connection with the circuit, whereas the plate 1 engages a spring contact 15 which also serves as a stop by engaging lugs 19 on the plate 1. In Figs. 5 and 6, the movable, plate 22 carries a knob 26 for adjustment, and is pressed by a spring 27 against a washer 35 serving to connect it in the circuit. The fixed plate 20 is in connection, by means of screws 31, with a ring 30 apertured at 32 to receive a plug 33 for connection in the circuit. A pin or the like may be placed on the dial 4 to limit the movement of the plate 22 which also carries a pointer 29 co-operating with the index on the dial.