deadbolt lock - please help

[digital_blue]

You know... as much as I appreciate the accolades, vector actually explained it several posts before me.

db

[vector40]

I'm starting to think that too much internet has stripped me of technical writing skills. Maybe I should hole up in the Alps for a month with a stack of Hemingway and a ream of notebook paper.

[Obex Imperium]

I saw this post and tried my hand at the challenge. This is my first post and I'm new. Hope you enjoy 8]

[Wade]

what is the purpose of the half-cylinder looking thing in front of the latch?

That's what makes it deadlatch. When the door closes, the actual latch goes through the hole in the strike plate, but that little "finger" stays depressed. In this position, the latch can not be pushed back, thus preventing slipping the latch.

Hope that clears it up.

Cheers!

db

I have slipped locks with these "fingers" and they didnt seem to offer any resistance to slipping. er, the door was locked

[Wade]

didnt "alon"(started the post) start a new thread about this same topic... anyways, I think db locked it.

[Wade]

I am posting this so I can get my post count to 50. Maybe then I'll be allowed into the advanced section

p.s. - sry for triple posting

[vector40]

I have slipped locks with these "fingers" and they didnt seem to offer any resistance to slipping. er, the door was locked

For a deadlatch to function properly, the door has to be decently fitted. If there's too much space between the lock and the jam, it won't press the latch far enough back, and it won't deadlock... and if it's REALLY bad, the deadlatch might just fall into the strike, accomplishing nothing at all.

[Obex Imperium]

This link should be easier to see. Sorry about that lack of definition before.

http://i35.photobucket.com/albums/d193/Limelit/41.jpg

[foo]

I think there's merit to your idea Omi. I actually would envision a knobset that functions this way. When the interior handle is turned the deadbolt retracts and stays retracted until the door is closed, perhaps triggered by the door jam. Something like that.

I used to work in a place with a lock that worked like this.

It wasn't a knobset, but rather a "jimmy-proof" deadbolt setup. It looked sort of like these:

http://nuset.com/productimages/2015-20-25.jpg

The mechanism was spring loaded. The bolts wanted to be "locked" all the time. You opened the door by turning the key (or interior knob) against the spring, and pushing the door open.

When the lock was clear of the door frame, the bolts were restrained by a catch mechanism.

On closing the door, part of the door frame's external strikeplate poked into the lock body, releasing the bolts which sprang shut.

It was possible to "lock" the bolts with the door still open, either by poking the mechanism with a pen, or by turning the key/knob just *barely* enough to open the door without triggering the catch.

I never saw that happen by accident, but you could do it on purpose, if you tried.

/foo

[workstation]

This is a very good discussion.

I don't really have much to add, but if anyone out there is designing an automatic lock, whether an entrance knobset, leverset etc or a nightlatch, they should certainly make sure to use some sort of mechanism with deadlocking functionality as described in this thread.

Having a bolt that an intruder can push back is just shameful on a modern lock. Nevertheless, people don't seem to want to pay extra for quality, and lock manufacturers don't seem to be able to make quality affordable, so we all generally end up with junk...

[NDEFreak]

Just to whet the appetite of those concerned with an automaticaly projecting deadbolt functions, there is a model of Abloy mortice lock ( the exact part number temporarily escapes me ) which has a square deadbolt that is fired into the strike by a smaller "trigger" just above the deadbolt on the faceplate when the door is closed. The closing action depresses the "trigger" and allows the deadbolt to project into the strike. The key retracts the deadbolt upon entry and the bolt is held in place until the "trigger" is activated again.

I know it is not the traditional cylindrical deadbolt we all know but a deadbolt none-the-less and an automatic one at that.

I dont know if Abloy are still currently making this model of mortice lock.

[workstation]

NDEFreak,

Yes, I have seen an Abloy lock like that. Just to clarify, presumably on the lock you're talking about, not just the key, but also the inner handle can retract the bolt? i.e., it's not a cell lock for an institution!

I think your description of the "trigger" may be slightly wrong in this case (although you may of course, be talking about a different lock). Does the trigger look like an ordinary rectangular-wedge-shaped latchbolt, albeit maybe smaller? If so, I think it's depressing the trigger, _then releasing it_ that shoots the deadbolt. (The latchbolt drops into its own hole in the strike-plate.) This ensures that the deadbolt locates properly. I actually thought this was how all deadlocking automatic locks that have two bolts worked, until I saw the picture of the Ingersoll above.

All this stuff is very hard to describe, isn't it?

[NDEFreak]

Difficult - yes. Especially when you get caught up in using your own terminology, which is right and wrong at the same time, depending on your location!

Also, regarding the little "wedge" shaped trigger - yes, you are quite right, although it still needs to remain depressed to a certain degree in order to act as a "deadlatch trigger" to prevent the bolt being forced back, confusing perhaps, but I hope you know what I mean. Terms and industry definitions are a little varied down here in OZ, a mix from the UK and the USA and our own I think.

[C locked]

I know i'm posting on an old post. But having taken the deadlatch (pictured above) apart. I can say. On The shaft that allows retraction of main latch is a square cutout. and on the shaft of the D Latch (deadlatch) is a similar cutout with an angled edge, to allow it to push the "locking pin" out of the way. And of course there is the spring loaded "locking pin" which is actually not a pin but a roughly L Shaped piece of steel with the end bent over with the bent piece being the size that fits the cutout. Which is springloaded with a tiny spring like a peg wrapped around its pivot.
...When the deadlatch is depressed its cutout aligns with the mainlatchs cutout allowing the locking pin to drop into it. Viola. Locked.
...when the knob is turned it retracts the deadlatch which lifts the locking pin out of the way. And then retracts the mainlatch. Viola. Unlocked and open.
...it is a little over simplified. But. Basically that is what is happening inside the latch. ...it is so much more difficult to describe. Without a diagram.