My landlady recently had a new vestibule door installed in my apartment building. Unfortunately, the Keystone Kops she hired installed a mortise lock with a spring bolt that can be jimmied open with a credit card or other piece of stiff, flexible plastic.
I want to encourage her to have the installers switch it for one of those locks with the little curvey-wedge-shaped lever that detects when the door is closed and immobilizes the spring bolt so that it can’t be slipped open. What exactly is that feature called?
It’s called a “jimmy proof” bolt or latch. There are several different types, but I don’t know the specific names for each. They all serve the same basic function.
I don’t think that’s it. At least not according to what I turned up when I did a web search using that term. “Jimmyproof” seems to refer to one of those surface-mounted locks with a multi-fingered bolt that literally interlocks with the female-type catch that is screwed into the jamb. IIRC, they used to call those Segal locks, named for the company that introduced them.
That’s one type of jimmy proof lock, but not the one I meant. I’ve been searching around and found the one I think you mean is called a “dead-latch,” like This one. That it?
A springlatch is a single tongue which engages the strikeplate, typically found on interior passage and privacy locksets. A deadlatch is a springlatch with an additional member held in when the latch properly engages the strikeplate. Half-round, it sits against the latch on the side to which the door swings.
Jimmy-proof can take many meanings, including the Yale 197 1/4 surface mounted rim boltlock, or the similar 600 series offering by Segal.
The hardware pictured in Q.E.D.'s link is a full mortise lock, incorporating passage latching, as well as deadbolt function.