Does anybody make door knobs that allow exit yet remain locked?

[jaysonc]

I did not think about loading of the strike either initially, so I didn't fix it. I was lucky. My wife and I found that this "Feature" fixed our laundry door issue.

When we unlock the strike. It will click like normal, but does not actually unlock. To finish the unlock process you have to remove the pressure created by the door seals. My wife and I do this by either pressing then pulling the door slightly. (or the opposite depending on the door). This releases the pressure and allows the strike to completely unlock.

This works with my laundry issue because when we just walk by the garage door to the laundry, the strike will click, but since we do not relieve the pressure it does not finish the unlock. We let the timeout will re-lock it.

To get around this behavior, you can purchase a "loadable electronic strike". These will completely unlock even if there is pressure on them. I know that a company called HES makes one. There may be others.

A final item to note about my install is that on rare occasions, the door can open on its own. I have tracked this down to the convergence of some rare factors. My laundry door issue and the fact that modern homes are very tightly sealed. I have noticed twice in 1.5 years that high wind conditions can cause an issue.

When wind passes by my garage door, it creates negative pressure on the outside of the door and relieves pressure on the strike. Also, if the wind blow over my chimney, it can create negative pressure on the inside of the door.

So combine these three situations in the correct order...

1. Wind starts blowing by the garage pulling on the door closed.
2. Walk by the door RTE motion triggering the strike to unlock.
3. Wind stops blowing by the garage before the strike auto-relocks. (this allows the door seal to push the door past the strike lock position).
4. Wind over the chimney starts to blow and pulls the door open.
5. Oops!.

I do have a plan to resolve this issue using a small maglock. My plan is to power the maglock for just a second every time the strike has relocked. I am planning to use the magnet to pull the door closed far enough that the strike completely locks. I do not plan on using the maglock to secure the door.

Unfortunately, I am still awaiting a building permit from the wife. She does not like the look of a maglock.

 

[gatchel]

..... I think I would have put in a big red 'request-to-exit' button instead of the motion detector.

This is the "Push to Exit" green button we use at work to get out of our server room that has maglocks if we forget to badge in. Works well. There are variations of the same thing

Be careful using those buttons. They might violate fire code egress rules. Typically you have to be able to exit the door with no special knowledge, and in one action. Also, they should have an exit delay built in. If they don't you have to press the button and also press the door at the same time. Most fire marshalls in our area don't like buttons unless they are air bladder types. Some of them don't even like the air bladder delay units.

 

[scriptx]

I found a fairly intelligent design but you pay for the craftiness of it. Unlike typical systems, it pushes the door knob's latch in towards the door so you can just push it open. The benefits that I see are: it fits a standard cutout (the 4.5" one anyway) and it opens even with preload pressure. However, at 200 bucks a pop, I may wire my doors and just do a single one this time around. I have a few emails into various sites to see if some of the cheaper ones take a little load and still open. I'll post if I find anything out.....

The name of the latch I found: Securitron Unlatch.

 

[tmbrown97]

scriptx - if I'm following what you're describing, that could actually be an issue. Interior non-locking doors let you push the latch in - but most lockable entry/exit doors have a mechanism that keeps you from pushing it in - to keep people from credit-carding the door to open it. If you look at an entry latch, there's the larger latch then the little bar that piggy-backs the latch. When the door is open, both of those parts are fully extended allowing you to push both in together (to close the door). However, a properly aligned door will only let the larger part of the latch extrude, keeping the smaller bar depressed. In that state, the larger latch cannot be pushed in (try this on your front door).

I have the schlage latches Steve mentioned - cheaper entry latches, but their default behavior lets you exit freely while still locked from the outside. It's because of that we keep a lock-box around!

If you're ok with that sort of single latch (without the deadbolt), I'd personally look at some sort of commercial equivalent and make sure the frame is secured well enough to prevent a simple kick-in. Then again, that's where the alarm comes in for backup - we all know door locks only keep the nuisances out - true thiefs are breaking something down no matter what.

 

[jaysonc]

Todd,

I think the poduct Scriptx found deals with that sitaution, but they only explained it in the PDF here..

It has two servos One that normally stays depressed and one that stays extended. The normally extended servo was specifically to keep the deadlatch pin depressed. When you unlock the strike, it would let the deadlatch pin (the small bar) extend then it will depress both latches at the same time.

I think you bring up an excellent point though. For the longest time I did not understand the importance of how precisely a door latch system needed to be. I did not know that the smaller pin should remain depressed when the door is closed or the lock would be less secure.

--
Jayson

scriptx - if I'm following what you're describing, that could actually be an issue. Interior non-locking doors let you push the latch in - but most lockable entry/exit doors have a mechanism that keeps you from pushing it in - to keep people from credit-carding the door to open it. If you look at an entry latch, there's the larger latch then the little bar that piggy-backs the latch. When the door is open, both of those parts are fully extended allowing you to push both in together (to close the door). However, a properly aligned door will only let the larger part of the latch extrude, keeping the smaller bar depressed. In that state, the larger latch cannot be pushed in (try this on your front door).

I have the schlage latches Steve mentioned - cheaper entry latches, but their default behavior lets you exit freely while still locked from the outside. It's because of that we keep a lock-box around!

If you're ok with that sort of single latch (without the deadbolt), I'd personally look at some sort of commercial equivalent and make sure the frame is secured well enough to prevent a simple kick-in. Then again, that's where the alarm comes in for backup - we all know door locks only keep the nuisances out - true thiefs are breaking something down no matter what.

 

[scriptx]

Todd you are absolutely correct, although, I didn't realize knobs worked that way until you mentioned something and jaysonc pointed out the PDF.

I sent an email into Seco-Larm, they make an $84 unit, the SD-994C. I got a response that they have never heard of that model not opening. I'll likely bench test it while simulating some pressure and trigger it to open. At nearly a third of the Securitron device, it is a very attractive option.

If it doesn't work, I'll only be out the ebay/paypal fee unless I can get a place to agree up front to take it back if I bench test it first.

I'll let you guys know how it turns out.

 

[tmbrown97]

Well how ingenious of them! Glad it's covered - just wanted to bring it up to be safe. Thx for the info Jayson.

I don't know why I know how things like that work... guess I have a curious or mischievous mind... You'd be surprised how many doors aren't quite properly aligned enough to keep people from credit-carding them. Quite often you can slip your credit card around the bend so it's ready then give the door a really hard pull to pull that little rod into the hole so it fully extends - then push your credit card the rest of the way to pop the door open. If it's your door, make sure that there's no way the door can be pushed that far forward be aligning the strike-plate appropriately.

 

[scriptx]

I wanted to give everyone an update. I ended up buying some Seco-Larm Heavy Duty electric door strikes SD-994C since they were a few hundred dollars less and going on what Seco-Larm stated that they have never had an issue.

I installed the first one this weekend and it is exactly as jaysonc posted. You have to pull the door in a little bit for the lock to disengage. It isn't always that way because the strike portion has about 1/16" of play in it.

Either way, I don't like it because I'll have to give people instructions on how to open the door. I did some research and found an alternative, the HES 7000 that accommodates a 30lb preload on the strike while maintaining its ability to open. I ordered one this weekend and hopefully I'll be able to post its result. It was about $150 with the face place.

I'll keep everyone posted on how well it works. Hopefully there won't be much more work in the way of chiseling!

 

[Lisa]

I thought you need mechanical lock, that is having key to open from the outside, If i am right, what you need is Rim Locks. or go with some professional or local locksmith, may be they will help you out.

 

[scriptx]

OK, the last chapter in this novel. I put in an HES 7000 last night and it works flawlessly. Even pulling back on the door while engaging the strike the strike still opens!

It is a little bigger than the seco-larms, but not bad at all.

Lisa, I found that most of the Schlage door knobs will allow you to open the door from the inside while the outside remains locked. Using Fail Secure strikes then allows the doors to always remain locked while still support egress in case of emergency.