Is there a name for cordless drills that lock the chuck when off?

[tinnews]

Is there a special name for the type of cordless drill where the chuck is prevented from rotating when switched off?

I don't mean a specific chuck lock device, I mean where (like on my Metabo cordless drills) where the chuck is locked automatically when the drill isn't rotating so you all you ever have to do is twist the chuck to add/remove tools, there's no separate locking action required and you don't have to use two hands on the chuck.

[Phil]

Normal?

[John Rumm]

These are often described as "one handed" or "single handed" chucks. Found on the better drills. Cheaper ones have the tow section counter rotating type that need two hands. Alternatively the chuck does not get a mention and the drill spec includes "auto spindle lock" or similar.

[dom]

I think I've seen auto-lock, and single-sleeve.

[Steve Walker]

Do you mean that once it stops rotating it locks automatically until you start the drill again? I've not seen that, but my Bosch locks when the direction control is in the centre position.

SteveW

[tinnews]

It locks automatically so a 'single sleeve' keyless chuck can be turned without having to explicitly lock the drill. I have this on my Metabo drills and I've seen it on a few others.

[dennis]

I have a B&D that locks. Its a shame the battery is knackered.

[Andrew Gabriel]

Uses a bidirectional back-stopping clutch, so the bit/chuck locks solid if you try turning it by hand, but rotates when the motor drives it (see the thread "source battery for screwdriver")