| 摘要 |
<p>661,704. Sheet feeding apparatus. SOC. NEBIOLO. April 20, 1949 [April 28, 1948], No. 10524/49. Class 100 (i). In an automatic apparatus for feeding sheets to a printing-machine, in order to prevent more than one sheet being fed at a time, or prevent more than the desired number of superposed sheets being fed together, according to the type of feed, the sheets are passed between two conductive plates 2, 3 which constitute the plates of a condenser which is connected in a circuit sensitive to capacity variations and which controls a member, e.g. a switch, on which the operation of the machine depends. As shown, a metal plate 2 is inset on a non- conductive feed board 1, and an opposed metal plate 3 is carried by an adjustable means 4, 6 in an arm 7 secured on a rod 8. These plates are arranged in a detector circuit B including a triod valve, variable condenser, reaction coil, etc., and a relay which controls a switch in the control circuit of the machine. When an extra sheet is fed, the increase in capacity of the condenser 2, 3 causes a rapid excitation of the oscillations of the valve, a corresponding drop of anode current, and subsequent release of the relay controlling the switch.</p> |
