Rotational Lockout

1. An apparatus comprising: a unit insertable into an enclosure having a first component, the unit comprising: a second component; a shaft operably coupled to the second component to linearly translate the second component between a first state connected to the first component and a second state disconnected from the first component in response to rotation of the shaft; and a rotational lockout mechanism configured to lock the shaft against rotation and to unlock the shaft for rotation in response to a mechanical reaction between the enclosure and the unit that occurs when the unit has been sufficiently inserted into the enclosure such that the second component is proximate the first component.

2. The apparatus of claim 1 , wherein rotational lockout mechanism comprises: a keyed guide associated with the unit; and a movable plunger keyed to the guide against rotation and configured to contact a fixed physical stop surface of the enclosure upon insertion of the unit into the enclosure, wherein the plunger is movable relative to the shaft between a first position in which the plunger locks the shaft against rotation and a second position in which the shaft is rotatable relative to the plunger.

3. The apparatus of claim 2 , when the plunger is resiliently biased toward the first position and wherein insertion of the unit into the enclosure on the plunger is in contact with the fixed physical stop surface moves the plunger against a bias to the second position.

4. The apparatus of claim 2 , wherein the plunger includes a slot having an axial portion axially along the shaft and a circumferential portion at least partially about the shaft and wherein the shaft includes a projection movable within the slot.

5. The apparatus of claim 4 further comprising a spring captured between the projection and the plunger to resiliently bias the plunger towards the first position.

6. The apparatus of claim 1 further comprising a unit lock that, in response to rotation of the shaft, is actuatable between a locking state in which the unit is locked to the enclosure when in the enclosure and an unlocked state.

7. The apparatus of claim 6 wherein the unit lock comprises a latch configured to prevent insertion of the unit into enclosure when the lock is in the locking state prior to insertion of the unit into the enclosure.

8. The apparatus of claim 1 , wherein the unit is insertable into the enclosure in a first direction, wherein the shaft is rotatable about an axis parallel to the first direction and wherein the second component is linearly translatable in a second direction perpendicular to the first direction.

9. The apparatus of claim 1 , wherein the first component and the second opponent comprise first and second electrical connectors, respectively.

10. The apparatus of claim 1 , wherein alignment of the first component and the second component are not visible to an operator when the unit is within the enclosure.

11. The apparatus of claim 1 further comprising the enclosure having the first component.

12. The apparatus of claim 11 , wherein the enclosure comprises a computer blade enclosure configured to receive a plurality of computer blades and wherein the unit comprises one of the computer blades.

13. A method comprising: inserting a unit into an enclosure having a first component, the unit having a second component; unlocking a shaft for rotation automatically in response to a mechanical reaction between the unit in the enclosure upon a predetermined extent of insertion of the unit into the enclosure; and rotating shaft to linearly translate the second component into connection with the first component.

14. The method of claim 13 further comprising locking the shaft against rotation using a keyed guide associated with the unit and a movable plunger keyed to the guide against rotation and configured to contact a fixed physical stop surface of the enclosure upon insertion of the unit into the enclosure, wherein the plunger is moved relative to the shaft between a first position in which the plunger locks the shaft against rotation and a second position in which the shaft is rotatable relative to the plunger.

15. The method of claim 13 , wherein the enclosure comprises a computer blade enclosure configured to receive a plurality of computer blades and wherein the unit comprises one of the computer blades.