Function of the Disconnector
"How does the disconnector work?" I get that question a lot, so I thought that it might be a good topic for those seeking understanding of the gun.
Its technical name is "The Disconnect"... but it's actually more of a connector. I've often said that it's a connector AND a disconnector, since a true disconnector only arrests the hammer until the trigger is released, and allows it to fall back to the sear so that another trigger pull can fire the weapon. Among the simplest of true disconnectors is the one in the AR-15 rifle and its clones.
When the pistol is in battery and ready to fire, the disconnect is positioned between the trigger stirrup and the backside of the sear legs. When the trigger is pulled, the disconnect is pushed into the sear, causing it to rotate off the hammer hooks, and the hammer falls. If the disconnect is removed, the hammer will cock, but pulling the trigger won't drop the hammer, because there's nothing there to bridge the gap between trigger and sear.
When the slide moves rearward in recoil, the disconnect is pushed down into the frame by the center rail in the slide. When the disconnect is pushed downward, it drops below the sear legs, and the sear is now able to rotate back into position to catch the hammer hooks, and hold the hammer at full cock position. Since the disconnect is designed to allow a two axis movement... up/down and fore/aft... it continues to move rearward a little further, and is captured by the bottoms of the sear legs until the trigger is released... and then rotates forward enough to allow it to also be pushed upward so that the top of the disconnect sits in the half-moon shaped slot in the slide, and connects the trigger and sear, making the gun ready to fire again.
This two-axis movement is provided by the center leg of the sear spring, located in the grip frame. This spring is a three-pronged leaf spring that also resets the sear and grip safety. The spring imposes tension on the disconnect in two directions at once by means of a 48 degree angle on the backside of the disconnect body, just above the paddle. The leaf pushes the disconnect forward to free it from the sear legs, and works with the angle to also move it upward.
If the disconnect is worn, or out of spec... and can't move downward far enough to break the connection between the trigger and sear, the sear can't reset. (Unless you're quick enough to release the trigger before the slide starts to move forward after it recoils.) The hammer can't cock, and it will follow the slide. For this reason, the top of the disconnect should never be filed or stoned, other than to dress a sharp edge or burr at the corners. The tip shouldn't be touched, other than to polish it lightly on a non-aggressive material.
I like denim with a little J&B Bore Cleaner imbedded into the cloth, and denim alone will often produce a nice burnish if the part is buffed briskly on the material.
If the disconnector is too long, and can't move far enough upward into the slot, it can't make connection between trigger and sear. The hammer will cock, but the gun won't fire. This is where many people get into trouble with the disconnect. They figure out why the hammer won't fall, and shorten the top of the disconnect, only to discover that the hammer follows the slide... or in some cases, the gun goes into full-auto mode. I'll repeat the warning: The top of the disconnector should never be filed or stoned. If it doesn't move into firing pisition, the half-moon slot should be made deeper. There is a scraper available from Brownells that is designed specifically for this purpose.
In case anyone gets the idea that they'd like to play with the disconnector length in order to purposely cause the pistol to fire in the full-auto mode... be warned... The gun can fire out of battery, and do serious damage to the slide, frame, magazine, your hand, your eyes... or all of the above. It's also illegal. Purposely modifying any firearm with the intent of creating a machinegun can land you in deep trouble unless you live in a Class 3 state, and you have done all the required paperwork. I strongly advise one and all to forget this little trick.
Tuner, been working on my Springfield and have a problem. When I manually dissengage the slide and pull the trigger the hammer falls. Does my new disconnect need the slot scraped to allow for more movement?
I'm a little corn-fused. When the slide is in battery and you pull the trigger... does the hammer fall to half-cock? When you hit the slide release with the trigger held back...does the hammer fall without releasing the trigger and pulling it again?
With the hammer cocked and safety off. I pull the slide back an eighth of an inch and puul the trigger and the hammer goes. I believe this means the diconnect isn't working properly. If I bring the slide back 3/4 of an inch and pull the trigger the hammer falls. The disconnect I installed isn'e working properly I believe. All else is working fine. The safety, beavertail, and so on. The gun simply can fire unlocked.
That's a bad thing, lil toad. Either somethin' is bad out of spec or the disconnect is worn. Check your PMs.
The bending of the sear spring did nothing, so I figured hammer and sear, like you said. Ordered a matched set from McCormick but found out too late that they required a beaver tail grip safety. .250 radius which my Springfield does not have. I told them I was not into filing and milling a perfectly good gun. Then asked if the sear would work with the original hammer and was told yep. So I sent back the hammer and with friend installed the new sear. BTW hammer hooks are 020 and at 90 degrees to hammer. Had to back out the Videki trigger set screw 3/4 turn. All seemed ok with no hammer dropping, Took it shooting and found a longer slack, a very definite "click" and them the hammer would fall. Little harder trigger pull also.
Decided that my buddy and I are not gunsmiths and that life is too short to keep on fooling around, since I certainly don't have your knowledge ( your disconnect discussion was impressive)
Talked to Debbie at Springfield and the gun goes to them on Monday. I'd rather shoot then fiddle.
Try backing the set screw out another half-turn. The click, may be due to the trigger needing a little more travel. There's also a built-in trigger overtravel stop in the gun that may require a slight adjustment. Rare, but it happens. It's the shoulder underneath the grip safety lug that blocks the trigger. If the stirrup hits that abutment a little too early, that can cause a problem too.
Good grief! I read my last message and sure wish I had editied it. Late night writing equals many mistakes.
I appreciate the guidence and maybe should have backed out the screw some more, but then the other problem may have surfaced. There I would be playing gunsmith again.
Since you don't live near Huntsville, I'm going ahead with my plan and mail the sucker back to Springfield for their experts to fix.
I have had the gun since 1992 and fired a bunch of rounds through it. There may be other items needing a look see.
This is too nice a gun to piddle with and one that is a jewel to shoot.
Disconnector question/problem. Just finished build ing a SS Essex's commander and took it to the range yesterday and today. Shoots good eats everything I run through it.
But I noticed one strange thing. When you load the weapon pull the slide back and squeeze the trigger the hammer will not disengade and fire until I let off the trigger and then re-squeeze then it works fine and all the rounds in that mag fire with no problem. Load a new mag pull the slide back and the same thing happens. Removed the slide cocked the hammer pushed the disconnect down as if the slide had worked. Pulled the trigger observed The disconnect do a little movement but would not work until I let off the trigger and reapplied pressure and it works. ?
Sounds like it's not resetting. The second trigger pull adds tension to the sear spring and pushes it into the connected position.
Check:
Trigger stirrup for roughness.
Disconnector mating surface on the spade for same.
Check to see that the disconnect is moving high enough into the timing slot.
Smooth trigger movement fore and aft. (Should move freely of its own weight.)
Disconnect movement free throughout its travel up/down.
Slide in full battery? (Repeat the malfunctioning condition and and bump the
rear of the slide before pulling the trigger the first time.
just polished the disconnector well a little and changed sear springs danged if I don't think it's working correctly now.
Quote:
just polished the disconnector well a little and changed sear springs
danged if I don't think it's working correctly now.
Yep. it's usually somethin' simple.
Go ahead and polish the rear face of the trigger stirrup and the face of the disconnector spade on a piece of 600-grit wet-or-dry paper backed on a flat, hard surface. A glass plate will do. Polish with a figure "8" or a circular motion. Break any sharp edges that you can find. Polish the sides of the trigger bow in a straight line on the paper... fingers on the inside of the bow putting pressure on the side being polished. Use light oil on the paper for a better finish.
Polish the angle on the back of the disconnect spade in straight up/down strokes, and be VERY careful to maintain the angle. It's critical. Pull it down the paper... stop... lift... go back and repeat.
Polish the tip of the sear spring on a matching angle with the one on the disconnect. Just a little will do, so don't get carried away.
Thanks, have been doing some polishing on them tonight. this stainless steel is rough and will take some polishing.
If there are deep toolmarks, don't try to get'em completely out. Just smooth up the high spots.