Browse Prior Art Database

Card Latching System With Positive Retention

IP.com Disclosure Number: IPCOM000122121D
Original Publication Date: 1991-Nov-01
Included in the Prior Art Database: 2005-Apr-04
Document File: 7 page(s) / 182K

Publishing Venue

IBM

Related People

Valle, VE: AUTHOR [+2]

Abstract

The latching system described in this article is intended to address installation and removal of high pin count cards to a backplane along with a method for positive retention of these cards once installed.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 52% of the total text.

Card Latching System With Positive Retention

      The latching system described in this article is intended
to address installation and removal of high pin count cards to a
backplane along with a method for positive retention of these cards
once installed.

      In packaging applications where multiple cards are
interconnected to a backplane:
           Installation or removal of a card is often difficult due
to the design of the latch. Depending on the design of the latch, the
latch may not aid in card installation or removal. Installation and
removal of cards should be a simple operation both in manufacturing a
system where a card could be removed or installed several times, or
when servicing a machine in the field.
           Card retention is minimal or not present.  In some
instances, the latch may not have provisions for locking the card in
place or the latch may only "snap" into place to keep the latch
secured to the card.  Card retention becomes a major issue when
shipping configured and tested systems.  Upon delivery, all cards
should remain plugged into the backplane.
           User feedback that a card is installed correctly is often
vague.  In some designs, the latch "snaps" into place indicating that
the latch has reached its designated stop.  In other systems, there
are no indications that installation is complete.

      The latch and latching concepts presented in this article
provide one concept for addressing the design points above.

      Fig. 1 shows one of four latches developed.  These four
latches, which are similar in design, provide two different lengths
and widths to address varying packaging requirements.  The latch
consists of two parts, the base "latch" and the "lock."  These parts
are shown in Fig.  2.

      The lock slides up and down in the latch (Fig. 2) to provide a
locking feature.  When the lock is "up," the latch is unlocked.  When
the lock is "down," the latch is locked.

      Assembly of the latch and lock is accomplished by snapping the
two pieces together.  The lock snaps into the latch and is held in
place by a series of small cantilever snaps.  The cantilever snaps
retain the lock to the latch in both locked and unlocked positions.

      Tactile feedback when installing a card is provided by
cylindrical ribs and grooves at each end of the lock.  When the loc...