Hot Topics: Antique Lock Out

The inner workings of an antique lock.

Here on we enjoy providing a place where home improvement novices and experts can come together to share ideas and advice. Inside our Forums, users can browse threads to see what exchanges are taking place on a topic of interest or start their own dialogue by posting something for the community to take part in. With over 250,000 members and counting, this resource is quite active so each week we highlight one of the conversations that may just help you with that next DIY project.

Many older homes still have antique fixtures and hardware, ‘cause they were made to last. But what do you do when they finally give out, and there are no standard sizes and replacement parts? If you’re a DIYer, you turn to the forum.

Original Post: Mortise door lock, handle turns but lock doesn't turn with it

jaycmw18 Member


I have an old style mortise door lock that stopped operating correctly. When you'd turn the handle, the lock wouldn't move in or out of the housing.

I opened it up to see what was going on inside, and I'm assuming something broke or is out of place. Before I spend time trying to fix this myself - is there something internal missing?

There's not much too it, and I think that's the problem. I'm just looking for the thing to operate so that when I close the door it stays closed!


Highlights from the Thread

czizzi Member

The two "ears" on the hub with the square hole in it should be on the same side of the fork. Whether on the inside or outside not sure, I would lean to the outside of the fork. Was there a spring somewhere on the fork mechanism?

rstripe Member

The cams (ears) on the hub (piece with square hole) orient at 12:00 and 06:00 o'clock on the inside of the latch fork, so that turning the hub either way retracts the latch. Like czizzi said tho, there should be a spring somewhere to bias the latch outward.

rstripe Member

This is actually not a mortise lock, but a rim lock... fairly common in early USA, it was a popular aftermarket choice, as it could be easily fastened to the inside surface of the door; a rectangular hole was cut thru the door for the key, using a small keyhole saw, (yup, that's how it got its name), and a round hole for the spindle. A toggle lever on top of the case would deadlock the latch, thereby locking the knobs, for "extra security."

With minimal or no warding, and a single non-gated lever, the keys were pretty much all the same, and if you lost yours, you just bought another one at the local hardware store. Those were the days when, at least in the Midwest, most folks didn't even lock their doors at night.

What is unusual to me is the use of a coil spring to bias the lever, rather than a flat spring... maybe this is the "Deluxe" model...

jaycmw18 Member

I did not see any spring mechanism, the only thing I saw on the inside when I took it a part was a small steel bar that went from one end to the other. It does appear like it broke off a little tab inside the lock. I drew a red line here to show where I think it was... does that make sense?

It seems to me, like czizzi said, I believe the ears went on the inside of the fork, and the steel bar applied downward pressure keep it in place. That's why on the one ear you can see it's worn.

So the door handle goes thru the square, ears at 12:00 and 6:00, and the metal clamp holds it in place so when you turn it the ear can pivot at the bottom and allow the top ear to slide when opening.

Hot Topics-Antique Lock Out (body)

czizzi Member

The ears should be located on the 9 o'clock side of the square hole and the spring mechanism would them keep the striker in the extended position. The ears would apply pressure to the fork and pull the striker inward. The spring, or metal would act as a stop mechanism as well as a return spring mechanism to keep the striker set in the out position. When the metal piece broke it allowed the ears to over rotate and slide past the fork to the position you see now.

rstripe Member

I don't see how a spring or bar can attach to the lower fork without interfering with the lower ear operation... however near the left end of your red line it is quite possible a boss or a protrusion of the cast lock case broke off that would have supported a flat spring, coiled is such a manner as to act on the flange just behind the latch bevel. It was common for these to break, as they were very strong, being the only spring used to return the knobs to "neutral."

The only replacement American bit key rim lock I'm aware of is by Ilco, and your local locksmith can get one... they're very cheap, and most likely won't match up perfectly to your holes in the door, as there was no national standard between brands in those days.

I hope you will not be depending on this lock for security.

jaycmw18 Member

Thanks for the info, I’ll give my local locksmith a buzz or take this down to him to take a look at.

Certainly not using it for security. That's what deadbolts were invented for! This is just a knob to our basement, no real worry if it doesn't get fully repaired.

rstripe Member

Well, this type of lock is pretty rare in my neck o' the woods, but I wouldn't be surprised if an olde-timey smithy on your side of the country actually stocks these replacements...

History note: the principle of operation of this single-action non-gated lever lock was dominant up until the late 1700's when double-acting lever locks were invented & began replacing them, but because of their low cost & simplicity, they were still commonly used on low-cost new construction up until WWII.

Keep the busted lock; the coil-spring design is rare... maybe the grandkids will get a kick out of it someday... oh... that's right, it's not electronic... oh well...

See all the info and advice at: //