Automatic Letter Opener

Overview

An automatic letter opener clears a mailroom's incoming post by shaving a hair-thin strip off one edge of each envelope, so the contents slide out without being nicked. You drop a stack on the feed deck and the machine pulls them through one after another, dropping opened envelopes at the exit and the trimmings into a tray. It works much faster than a hand slitter and, because it cuts a margin rather than slicing into the envelope, it rarely damages what is inside.

The cut is made by a spinning disc, not a fixed blade. The Cutting Head carries a hardened Cutting Disc on a bearing-mounted spindle; as an envelope rides past, the disc trims a narrow ribbon off its edge. How much it removes is set by the Depth Stop in the Guide & Edge Stop assembly, and the Edge Guide keeps the envelope square against the cutting line so the cut stays parallel.

Feeding is handled by the Feed & Transport, the trimmings collect in the Chad Tray, and the Control Board runs the motor and watches for jams, all powered through the Power Supply.

How it works

An envelope placed on the deck trips the Feed Sensor, and the Control Board runs the Feed Motor, a motor built on a reused Stator Assembly and Rotor Assembly that drives both the rollers and the cutting disc. The Feed Roller and Pinch Roller pairs in the Feed & Transport grip the envelope and pull it along the Edge Guide at a steady speed.

As the edge passes the Cutting Head, the Cutting Disc, turning on its bearing-mounted Disc Shaft behind the Blade Guard, shaves off a thin strip, with the Depth Stop limiting how deep it bites. The trimmed strip falls into the Chad Tray below while the opened envelope continues to the exit and stacks. If an envelope stalls, the Jam Sensor tells the controller to cut the motor so nothing binds against the disc. The Power Switch selects off, manual single-feed, or fully automatic running.