| 摘要 |
PURPOSE:To stamp at predetermined positions in front and rear ends of a sheet material only by changing over switches by a machine wherein stampings at both the front edge reference of the sheet material and the rear edge reference thereof are switched using the change-over switches. CONSTITUTION:Change-over switches SI-1, SI-2 are connected to respective front edge terminals a. In this state, when the front edge of a sheet material comes to the position of a detecting means 11, a light emitted from a light source 12 is interrupted and a current does not flow through a light receiving portion 13. Thus, a transistor Q1 is turned OFF and the collector voltage assumes an H level. Upon this, a mono-stable multivibrating circuit MMV1 connected to the collector of the transistor Q1 via the switch SI-1 issues a pulse thereby to trigger a timer T1 through an OR gate G1. A resistor R1 determines a time width of the timer T1. The timer T1 is provided for waiting that the front edge of the sheet material comes to the stamping portion, because there is a space between the detecting means 11 and the stamping portion, as well as for properly selecting a rising time of a solenoid SL adapted to drive a stamp and a position where the stamp is to be pressed against the front edge of the sheet material. |
