The UK Guild of Handymen

Tubular latches are used on almost every door in the land but the average quality of this simple and low cost mechanism leaves much to be desired.
Central to their operation is the cylindrical barrel through which the square section handle spindle passes.
Via a simple crank, this allow the door handle or door knob, by turning the spindle, to withdraw the latch and open the door.
However, as you can see in the photo below, the square hole in this little cylinder comes very close to edge at all the four corners of the square. This little metal cylinder turning in the metal case of the latch soon wears because there is no lubrication. The cylinder then disintegrates when one of the corners of the square wears to the edge of the cylinder. When it fails, pieces drop inside the latch.
With nothing to crank back the latch and additionally with pieces of metal jammed inside to foul things up you will not be able to get the latch to work.
Either this will happen when the door is shut or else the door will be shut after the latch has broken resulting in a door that cannot be opened …even if you take a handle off.
I have had clients phone up in despair at not being able to get into a room, or airing cupboard, or in some instances having children trapped in bedrooms.
Exasperated and frantic parents have virtually destroyed the door, or frame, or both to release their trapped children.
What can you do?
1) Buy good quality latches.
It’s true they don’t make these how they used to. The latch part of the locks on my doors still work fine despite being fitted in 1937 but modern ones often don’t last much more than a couple of years
2) Oil the latch periodically
This is difficult to do as you have to take off a handle on one side or the other of the door to get at the culprit cylinder.
3) If a door latch fails you can try to operate (i.e. withdraw) it manually by inserting a sharp object like a knife between the door and the frame to prod at the latch to try and withdraw it.
4) If all else fails it will be easier to mend the door frame than replace or mend the door so attack the timber of the door frame near the ‘keep’ (the metal bit where the latch engages in the frame) to release the door.