Browse Prior Art Database

Magnet Armature Motion Control for Noise Control

IP.com Disclosure Number: IPCOM000101081D
Original Publication Date: 1990-Jun-01
Included in the Prior Art Database: 2005-Mar-16
Document File: 2 page(s) / 57K

Publishing Venue

IBM

Related People

Portig, H: AUTHOR

Abstract

Disclosed is a design that reduces the impact noise of the armature of an electromagnet such as is used to control the motion of the "D-roller" used on the 4019 printer. A cam groove molded into the D-roller gear is used to control the motion of the clapper so as to prevent the gap from closing and to transfer some of the energy imparted to the armature by magnetic forces to the gear so as to assist with its acceleration.

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Magnet Armature Motion Control for Noise Control

       Disclosed is a design that reduces the impact noise of
the armature of an electromagnet such as is used to control the
motion of the "D-roller" used on the 4019 printer.  A cam groove
molded into the D-roller gear is used to control the motion of the
clapper so as to prevent the gap from closing and to transfer some of
the energy imparted to the armature by magnetic forces to the gear so
as to assist with its acceleration.

      Magnet 1 in Fig. 1 serves to control the motion of the
"D-roller" gear 3 used on the 4019 printer.  When not active, gear 3
is at rest, prevented from rotating by armature 2 at the detent edge
9 on the gear.  When a sheet of paper is to be launched from the
paper drawer, magnet 1 is energized for approximately 35 milliseconds
so that the armature moves away from edge 9 allowing spring 4 to
accelerate the gear clockwise.  If it were not for the outer surface
of cam groove 5 molded into gear 3, the gap 6 of the magnet would
close, making a loud impact noise.  The impact noise of closing the
gap is avoided and replaced by the lower impact noise of clapper 2
impacting gear 3 at the cam surface 7.  The maximum velocity reached
by clapper 2 is limited because some of the energy is used to
accelerate gear 3 by means of cam surface 8.

      Fig. 2 shows successive stages in the magnet actuation cycle.
After impacting the cam surface at point 7, the slope of cam surface
8 causes the...