Can someone explain how this old lock system works?

[digital_blue]

Hey guys,

Yesterday I came across something I'd never seen before and, quite frankly, it puzzles the heck out of me.

A friend of mine is renting an apartment in an old building downtown. I was over at his place and, of course, I was looking at the locking hardware - 'cause that's what I do - and I noticed something odd (at least, odd to me).

On the edge of the door, as you'll see in the picture below, there are two buttons. These buttons lock and unlock the thumb latch. So, if you push in the top button, the thumb latch will not operate.

The problem is, this system is in no way affected by using the key. So, when this button is pushed, the only way to open the door seems to be by turning the knob in the inside of the door.

The part that I don't get is that this seems to me to be a really bad system. It seems it would be far too easy to accidentally push the button and lock yourself out for good. And what's more, you wouldn't even be able to pick your way back in. It would appear to require you to use one of a variety of bypass tools (that I won't go into in the public forums).

So... my question is... am I missing something here, or is that legitimately how this system works? Does anyone have experience with a system like this? Are accidental lockouts common?


As you can see, the two buttons are just below the latch.


From the outside.


From the inside.

[zeke79]

If memory serves me correctly those two buttons should set the lock to either be locked each time the door is shut or allow it to stay unlocked until it is either locked by key or by the buttons again.

[unbreakable]

Agreed Zeke, oddly enough we have these at school. Only in a knob mortise style.

[zeke79]

Agreed Zeke, oddly enough we have these at school. Only in a knob mortise style.

Sounds right. The stuff I run across that is like that still is the old sargent 8 series if I recall correctly. I despies those lock sets.

[digital_blue]

Right. That makes some sense. In that way, it's similar to how a commercial key-in-knob can be set to operate.

However, at least with a key-in-knob, you can still use the key to get in. This system seems only functional if someone is actually in the apartment. If you were to push that button on your way out to, say, the laundry room, you'd be without a way back in. That's the puzzling part to me. If the thumb latch had a cylinder associated with it, this would make perfect sense. But.. it doesn't. That's what's confusing.

db

[freakparade3]

When I was a very young kid visiting my grandparents their house had these type of locks. I was to young to remember what they did exactly but I know I got in trouble alot for messing with the buttons.

[HeadHunterCEO]

Right. That makes some sense. In that way, it's similar to how a commercial key-in-knob can be set to operate.

However, at least with a key-in-knob, you can still use the key to get in. This system seems only functional if someone is actually in the apartment. If you were to push that button on your way out to, say, the laundry room, you'd be without a way back in. That's the puzzling part to me. If the thumb latch had a cylinder associated with it, this would make perfect sense. But.. it doesn't. That's what's confusing.

db

So... my question is... am I missing something here, or is that legitimately how this system works? Does anyone have experience with a system like this? Are accidental lockouts common?

Its confusing because it isn't right.
when the lower button is depressed you are in a store room func which means the thumb trim is inop BUT the key rotated CW will retract the latch . When the upper button is depressed you are in a entry mode and the thumb will retract the latch as long as the deadbolt has been thrown.

now what happens is is the door is starting to tweak it becomes harder and harder to retract latch with key until some of the guts break. then you turn the key CW and it will stop at a certain point but not retract.

assuming noone has tore apart the lock and attempted to "repair" it because then only god knows what could be wrong.

thats a yale mortise as the cylinder states and you can ID it by the ex trim

I reccomend practicing a dissasembly on a lock you don't depend on before attempting to repair or just service that one.

[digital_blue]

Thanks for that info HH.

Firstly, you needn't worry about me disassembling that lock. It's on my friends apartment door and I've no intention of dismantling it.

What you say makes sense, but I'll have to have another look at it next time I'm there. What we did do, as a test, was I pushed the button and sent him out in the hall with the key. He tried to get back in with the key to no avail. Granted, I'm not 100% confident that he tried turning both directions, but I'm pretty sure he did.

You see, the key (as far as I know) doesn't actually control the latch. Again, maybe I'm wrong, but that's what appeared to be the case. When he was out in the hall, all he was able to successfully do was lock the deadbolt portion of the locking system.

I'll have a closer look though next time I'm there.

Cheers,

db

[raimundo]

these locks were installed on houses with servants who would not have keys, such houses were seldom unoccupied completly. this way someone who was just going out for a short time could leave the door unlocked.

The type may also have been used in public buildings also. But there must have been a second way in!

[UWSDWF]

yeah do not take those apart... if it's like a baldwin insert it has explosive springs and parts that I have no idea where they go.... I have a box of parts if anybody's interested

[HeadHunterCEO]

I can tell you guys don't run across these often

You have not truly lived until you have cut a full mortise lock into a $9K mahogony slab .

I get $550 to cut in active and inactive trim on a set of dbl doors

[nothumbs]

Here's a newer version of the same style lock:

http://www.lock-depot.com/scripts/prodview.asp?idProduct=32

They can be set up in a variety of ways, take a read on the text that describes the lock options at the URL above. Or read the table of options here:

http://www.arrowlock.com/features/functions/locksets_h_s_m.html

[raimundo]

another thought that may have been involved is the interior privacy lock, where servants with keys are kept out by using the button to disconect a keyed opening. this would presumably have a person inside enjoying the privacy, or another door in that can be keyed.

[samfishers]

i think its like in a side door of a car, that you cannot open the door by the inside, but only by the outside

[UWSDWF]

works like that