postbearbeitende machine with the triggered barrier device

摘要

A mailing machine base 12 is adapted to have a postage meter 14 mounted thereon. The meter has a postage printing drum 64 and a drive gear 66 therefor, and has a shutter bar 72 movable in opposite directions through a predetermined distance for movement thereof out of and into locking engagement with the drive gear, the base comprising, structure for moving the shutter bar, a d.c. motor 140 for driving the shutter bar moving structure, a microprocessor 122, power switching structure connected between the microprocessor and d.c. motor, the switching structure including four power switches arranged in an H-bridge circuit configuration for driving the motor in opposite directions respectively corresponding to the opposite directions of movement of the shutter bar. The microprocessor 122 is programmed for (i) energizing the switching structure with a first signal for driving the d.c. motor in a given direction for a first time interval predetermined to cause the d.c. motor to move the shutter partially through the predetermined distance, (ii) energizing the switching structure with a second signal for driving the d.c. motor in the given direction for a second time interval predetermined to cause the d.c. motor to move the shutter bar substantially through the remainder of the predetermined distance, (iii) energizing the switching structure with a third signal for driving the d.c. motor in the direction opposite to the given direction for a time interval predetermined to cause the d.c. motor to decelerate movement of the shutter bar, and (iv) energizing the switching structure with a fourth signal for driving the d.c. motor in the given direction for a fourth time interval predetermined to move the shutter entirely through the remainder of the distance.