Browse Prior Art Database

Method to Increase Reliability of Latch during Engagement with Actuator

IP.com Disclosure Number: IPCOM000114332D
Original Publication Date: 1994-Dec-01
Included in the Prior Art Database: 2005-Mar-28
Document File: 4 page(s) / 90K

Publishing Venue

IBM

Related People

Boutaghou, ZE: AUTHOR [+2]

Abstract

A soft material is interposed between the actuator and the inertial latch contact area to increase the contact duration between the actuator and the latch after the initial rotational shock in order to reduce bouncing. Under rotational accelerations sufficient to dislodge the actuator, the inertial latch is designed to rotate in the same direction as the actuator to engage the actuator and avoid unlatching. During the engagement of the inertial latch with the actuator, the latch and actuator bounce for few milliseconds under the external excitations. Bouncing of the actuator and the inertial latch contributes to the likelihood of failure of the latch leads to slider disk contact.

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

Method to Increase Reliability of Latch during Engagement with Actuator

      A soft material is interposed between the actuator and the
inertial latch contact area to increase the contact duration between
the actuator and the latch after the initial rotational shock in
order to reduce bouncing.  Under rotational accelerations sufficient
to dislodge the actuator, the inertial latch is designed to rotate in
the same direction as the actuator to engage the actuator and avoid
unlatching.  During the engagement of the inertial latch with the
actuator, the latch and actuator bounce for few milliseconds under
the external excitations.  Bouncing of the actuator and the inertial
latch contributes to the likelihood of failure of the latch leads to
slider disk contact.

      The proposed solution attempts to increase the contact duration
during the first and subsequent contacts of the actuator and the
latch.  The increased contact duration keeps the actuator in the
latched position long enough to reduce the effect of the subsequent
excitations observed after the initial shock is applied and absorb
some of the contact energy.  A method to design such an interface is
crucial to a successful implementation.  A simple one degree of
freedom model is proposed to describe the bouncing between two
flexible bodies as described by Fig. 1.  The model is used to predict
both the number of bouncing and the duration of the bounces.  The
contact duration t sub 1 can be obtained from solving the following
non-linear equation:
  <A sub i> exp(- gamma <Omega sub o> t) sin(Omega t - <alpha sub i>)
=
   - <x sub st>

      A is an amplitude factor depending on the approach velocity,
the static deflection, and the damping in  the system.  Omega sub o
is the natural frequency of the combined system during contact.
Omega is the damped natural frequency of the combined system.  The
numerical simulation of an actuator latch using different contact
materials interposed between the actuator and the inertial latch
according to a design with no added soft pad.
  MASS (KG)     0.1000000000E-01
    K (N/M)     0.1000000000E+07
   K1 (N/M)     0....