Frictional - Elastomeric Shockmount System for Mechanical Isolation of A Fragile Device From Sources of Vibration And Shock
Original Publication Date: 1991-Feb-01
Included in the Prior Art Database: 2005-Apr-01
Rachui, RA: AUTHOR [+2]
Referring to Fig. 1, this article describes a method for rigid mounting of a fragile device 1 to a supporting cradle 2 which has appendages, such as support stud 3, to mount one or more mechanical isolation shockmounts 4 which, in turn, are supported by frame 5.
Frictional - Elastomeric Shockmount System for Mechanical
of A Fragile Device From Sources of Vibration And Shock
Fig. 1, this article describes a method for
rigid mounting of a fragile device 1 to a supporting cradle 2 which
has appendages, such as support stud 3, to mount one or more
mechanical isolation shockmounts 4 which, in turn, are supported by
shockmount 4 (Fig. 2) is comprised of an inner hub
6, an outer rim 7 and multiple nonradial spokes 8. It is significant
to the design of the mechanical isolation system that the spokes 8
are oriented in a nonradial fashion so that maximum radial deflection
is possible for a given diameter restriction of outer rim 7. This
provides a compact design which generates desirably low
force-deflection rates in the shockmount 4 because, at full
deflection, the outer surface of inner hub 6 can virtually contact
the inner surface of outer rim 7 as the nonradial spokes are buckled
and deflected aside. The nonradial spoke orientation also minimizes
spoke flexure in compression (which would otherwise generate
undesirably higher force-deflection ratios) and features spoke
deformation in tension and column- buckling modes which generate
lower force-deflection ratios for the narrow spokes 8.
See Figs. 3a
(at rest) and 3b (laterally deflected) positions.
Cradle 2 has features in the shape of a dome 9 adjacent to the side
face of each shockmount 4. During lateral displacement of the cradle
2 TOWARD shockmount 4, the dome 9 presses into the side face of the
shockmount that it moves toward, and the curvature of the dome
becomes a determining factor in the displacement of cradle 2 and the
damping characteristics of the system.
Figs. 4a and 4b, for lateral displacement of the
cradle 2 AWAY FROM the face of shockmount 4, the shockmount can be
designed to be either deflected or not deflected in the lateral
direction so as to effect a greater or lesser change in the lateral
stiffness and damping characteristics for a given shockmount size.
on the opposite side where the cradle 2 moves away
from the face of shockmount 4 can be similarly designed to be
selectively deflected laterally, either toward or away from the side
face of shockmount 4, providing dome-like contouring 10 on the
underside of the head of support studs 3 will cause deflection of
shockmount 4, while use of headless support stud 11 will allow
sliding of the headless support stud 11 within the hole of inner hub
6 for a less stiff lateral support system.
to varying the durometer and resilience of the
elastomeric material, the physical dimensions of the spoke 8, such as
length, cross-section and angle, can be varied to independently
adjust the force-deflection characteristics in both the axial and
radial directions relative to the sho...