| 摘要 |
<p>979,493. Electric selective signalling systems; counters. CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE. May 31,1961 [June 1, 1960], No. 19681/61. Headings G4D and G4H. [Also in Division G3] A device for stopping a rotating shaft in accordance with a perforated sheet programme comprises a cyclometer type revolution counter each of whose digit wheels acts as a selector switch. A precision switch operates with the least significant digit wheel to connect into the control circuit a further wheel rotating with the least significant digit wheel to enable a fraction of rotation of the least significant wheel to be taken into account. The programmed sheet is wrapped around a programme drum 12, having five conductive cylinders, one per decade, each having ten contact fingers 17 for reading the programmed, these fingers being connected to ten contacts closed in turn by the appropriate digit wheel of the revolution counter. The common wiper contact is connectedto the previous decade cylinder,Fig.3 not shown. The shaft, not shown, and the counter thus rotates until each wiper is on a contact marked by those fingers 17 selected by the programme. The output from the selected contact on the last digit wheel 11 of the counter (corresponding to tenths of a revolution) is connected over a precision rotary switch 13 to actuate a relay 14 which connects into circuit a further wheel 15 which carries ten cams, each of which closes ten contacts in sequence per revolution; thus, there are ten shaft positions which agree with the number programmed at the 0. 01 zone of programme 16, but the wheel 15 is only energized by relay 14 during the correct tenth of a revolution; thus the shaft stopping signal appears at 18 at a hundredth of a revolution determined by the programme and wheel 15. In a modification, Fig. 2 not shown, the programme is in a binary-decimal form and the counter is provided with sets of four changeover contacts instead of ten simple contacts.</p> |
