Sliding patio door handles break from time to time.
Replacing them is a job the homeowner can easily do especially using a universal style of handle that is designed to replace many older styles.
Surface mount handles usually have the patio door lock built right into the the interior handle, so all you need to be concerned about is matching the 2 holes already in the door with the holes in the handle.
The picture above shows a typical surface mount patio door handle with a hook style lock built into the inside handle. This lock has a grab handle on the outside as well.
This lock requires 2 holes 11/32" diameter going right through the patio door spaced approx. 6-9/16" apart.
(The diagram shows 6.575" but apparently no one told the guy who made the drawing that in the field you cant drill dimensions to 3 decimal places with a regular tape measure !)
The above handle is pretty much the same except the interior handle has a more squared off appearance.
The following locks are made with a 4-15/16" spacing between the bolts.
This is useful because many many old handles use that spacing. If for example you have an old steel mortise lock that is broken and impossible to find, you could install one of these surface mount handles.
The lock on the handle would replace the lock on the already in the door and the handles would bolt right on because the hole spacing is identical.
The first one has a very low profile inside and outside handle or pull. This is used when there is very little space between the patio door and the screen door on the outside.
It also helps if your curtains or blinds are close to the door on the inside and you dont want to snag them.
This one is available only in silver aluminum finish.
This lock has a thicker wooden handle and uses an anti lift feature. The metal tab, just above the hook sticks out so that when the door is locked, the patio door cannot be lifted up from outside to make the door unlock.
These locks have an even smaller spacing used by a few old patio door manufacturers
The interior handle is made of wood and the exterior pull is a very low profile that allows the screen door to easily slide past.