Roll-tape knife control for a tape-cutting apparatus in a mailing machine

Abstract

A tape cutting mechanism uses a bi-directional motor and a clutch arrangement. However, with the use of such a clutch in an inexpensive open loop control system, the dynamic energy stored in the motor armature at the initiation of the cutting sequence is greater than the maximum energy required and the maximum cutting energy requirements vary considerably. Leftover energy is removed from the system in order to prevent a large impact at the end of its stroke which may damage the clutch mechanism and to decrease the noise by controlling the bi-directional motor for oscillating a member for cutting a tape and for feeding the cut tape. The method comprises operating the motor for a predetermined length of time in a first direction at a predetermined duty cycle, reversing the motor for a shorter predetermined length of time for slowing it down, thereafter running the motor in the first direction while incrementally reducing the duty cycle to assure that the member has been moved to a maximum position in a first direction and to limit its impact as the member reaches the maximum position, and thereafter reversing the motor to move the member to a maximum position in the opposite direction. At least some of the times and duty cycles for operation may be stored in non-volatile memory.