MIWA PR-J.LA-CS locking direction defect inspection and repair

"Sometimes it doesn't turn in the locking direction."

My assumption was that it was due to salt damage since the sea is nearby, so at first I thought the cylinder was dirty, so I spray-cleaned it. But it doesn't improve. There is also a problem from the thumbturn side. Both are locked.

In that case, I tried spray cleaning the lock case, but it wasn't completely clean. This would be the end of normal work, but it just doesn't feel right. Although it would take some time to investigate the cause, I decided to take the plunge and disassemble the case. It's an old-fashioned LA case. It has many parts and is a somewhat complicated mechanism. This type has been disassembled for the first time in a while. Even if it can be disassembled, it takes some time to reassemble it. I don't really like it.

Open the cover anyway. The link part that connects the deadbolt and cam has a strange shape. This part pushes down the deadbolt locking lever, but sometimes it doesn't push down properly. In addition, the deadbolt is stuck because the deadbolt locking lever is not pushed all the way.

At first, I tried machining the tip of an oddly shaped link part, but it didn't go well. Next I removed the deadbolt. Upon closer inspection of the interfering part, it appears that the sheet metal bending process is a little rough. It seems that the machining accuracy of 0.1 mm to 0.3 mm is not achieved, so I used a file to add a chamfer. This has been improved.