door knob lockset dead latch and latch plunger

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mechanicx

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I had a Schlage locking door knob on my front door. The dead latch froze up. I took it apart and was going to just replace the dead latch, but found that I could get the same type of Schlage door knob that was nonlocking for about the same price. I didn't want a locking door knob anyway since I have a deadbolt.

I installed it and it worked well except the door didn't latch far enough in to be perfectly even with my deadbolt. The only difference between locking and nonlocking besides the cylinder is that the latch on the nonlocking doesn't have a separate latch plunger. The old door knob's latch plunger was closing the door tighter and inline with the deadbolt. I fixed that problem by bending the tab inside the striker plate out more (luckily my original stiker plate had a slot on the inside tab to easily adjust with a flatblade screw driver, while the new striker inside tab did not) this link shows the parts I'm referring to http://www.thisoldhouse.com/toh/photos/0,,20297849,00.html .

Now here's my question about the latch plunger. As I explained originally my latch plunger was latching into the striker and holding the door in more. But according to Schlage's instructions the latch plunger is not suppose to enter the striker plate hole. See step 7 here http://consumer.schlage.com/Project Documents/P515-302-SH2-c.pdf.

That doesn't make much sense. I thought the purpose of the latch plunger was to engage latch bolt to prevent it from being pried open from outside. How is it going to do that if it installed so that it is pushed down level with the striker plate? And also my door was a pre-hung with the door jamb striker and deadbolt mortise precut if I recall and everything lined up pefectly with the bolt plunger going into the striker hole and with no adjustments.
 
The half moon dead latch plunger is to prevent moving back the door plunger with a screwdriver, credit card, etc. (someone breaking in). This is achieved when the half moon plunger is pushed in and against the striker plate.

Since you bought a non locking door set, this is a moot point, correct?

If your metal bending trick on the striker plate doesn't work, you can buy an adjustable one.

This page explains the same thing: http://keylessentrylocks.com/index.php?main_page=product_info&cPath=56_57&products_id=29
Lockey-Spring-Latchbolt.jpg
 
Actually I don't understand the purpose of the latch plunger all together. As far as I can tell when you lock a door knob you really are only lock the knob from from being turned. The latch can still be pushed in since the door can be locked while open and then shut.

I guess you're saying the plate or striker pressing the latch plunger in locks the entire latch?
 
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Originally Posted By: mechanicx
Actually I don't understand the purpose of the latch plunger all together. As far as I can tell when you lock a door knob you really are only lock the knob from from being turned. The latch can still can still be pushed since the door can be locked and then shut.


Yes, you can lock the door while open, and then push it shut because the door plunger will still push in. Once that half moon dead latch plunger is pushed in AND held in via contact with the striker plate, then the main door plunger is locked in place and will not move.....thus preventing a burglar from using a tool to push it in.

From my link added above: "When the door is closed, the strike plate presses in the plunger and prevents the latchbolt from opening independently of the handle. When properly installed, dead-locking latchbolts cannot be opened by sliding a credit card between the door and the door frame."

YES, to your edited question.
 
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OK it all makes sense now if that's the way the plunger works.

I was almost going to install a dead latch with plunger into my non locking door knob set just to get the door to close tight and inline with my deadbolt, until I saw/remember I could easily bend the inner tab of the existing striker plate.
 
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Originally Posted By: doitmyself
Originally Posted By: mechanicx
Actually I don't understand the purpose of the latch plunger all together. As far as I can tell when you lock a door knob you really are only lock the knob from from being turned. The latch can still can still be pushed since the door can be locked and then shut.


Yes, you can lock the door while open, and then push it shut because the door plunger will still push in. Once that half moon dead latch plunger is pushed in AND held in via contact with the striker plate, then the main door plunger is locked in place and will not move.....thus preventing a burglar from using a tool to push it in.

From my link added above: "When the door is closed, the strike plate presses in the plunger and prevents the latchbolt from opening independently of the handle. When properly installed, dead-locking latchbolts cannot be opened by sliding a credit card between the door and the door frame."

YES, to your edited question.


Ha! doitmyself nailed it again!
But for locks without this feature, we can only hope the thieves have lousy credit.
 
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