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Storage Bridge Bay Specification 20
Version 2.0
2.2 Air Inlet and Exhaust Vent Locations
An SBB compliant enclosure MUST [16] provide airflow to the SBB canister in a manner that air will enter
the SBB canister envelope boundary through the area bounded by the air vent keepout shown in Figure
6. The SBB specification provides three air vent exit locations, air vent 1, air vent 2 and air vent 3. The
position and dimensions of the air vents relative to the SBB canister envelope are shown in Figure 5. An
SBB compliant enclosure MUST [17] provide airflow to the SBB canister in a manner that air will exit the
SBB canister envelope boundary at, at least one of the three exit air vent locations. SBB compliant
enclosures MUST [18] provide at least one exit air vent location. SBB canisters are not required to
operate with every exit air vent location. SBB canister designers may design their system to support only
one exit air vent location if desired. Further requirements related to cooling and airflow are given in
Section 4.
2.3 Lever Mechanism Requirements
The SBB canister lever mechanism comprises of a horizontal lever arrangement mounted at the top of
the SBB canister to control the insertion and extraction of the canister. The lever definition is restricted to
the critical operating dimensions to allow individual canister vendors scope for unique design in this area.
The levers may, for instance, be interchangeable components or customizable to a particular customers
requirements.
The length or number of levers is also at the vendor’s discretion and should be suitable for the insertion
force associated with the canister implementation and associated number of SBBMI modules supported (
see Section 2.3.1 and Section 2.5.6).
All supporting chassis structures MUST [19] be capable of supporting the maximum loading criteria
imposed. SBB enclosure slots MUST [20] be capable of accepting SBB canisters with dual levers.
The lever rotates through approximately 60 degrees from the open position to the closed position. In the
open position the lever is aligned such that the cam surfaces do not extend beyond the profile of the SBB
canister and the SBB canister may be inserted into the enclosure. In the closed position the lever is
aligned such that the cam surfaces extend into the structure adjacent to the SBB canister, retaining the
fully inserted SBB canister in the enclosure. It is RECOMMENDED that a stop feature is provided for the
lever mechanism to prevent over rotation.
Figure 9, Figure 10, and Figure 11 include a recommended reference design for a camming lever that
would provide the optimum canister insertion and extraction when used with the specified enclosure
interface dimensions.
2.3.1 Force Criteria
The lever mechanism is required to overcome the multiple pin insertion force of the SBBMI connector
system, plus the force required to compress both the canister and enclosure EMI gasket. The force
requirement will vary according to the EMI implementation from each enclosure provider but is estimated
to be around 270N for a full implementation containing SBBMI modules M1 to M13.
2.3.2 Mechanism Definition
Insertion of the SBB canister into the enclosure is controlled by the lever mechanism. The canister with
the levers in the open position is inserted into the enclosure. The lever primary cam makes first contact
with the enclosure structure and starts the rotation of the lever around its pivot point. This engages the
secondary cam into the enclosure feature. Manual pressure on the levers provides the mechanical
advantage for the cam to act on the enclosure feature and move the canister fully into the enclosure.