E-Stop PB with "Trigger Action"

dogleg43 · May 23, 2013

Does anyone know what "trigger action" would mean on an
Allen-Bradley E-Stop button?

Is this where to reset it you pull out on it and it's springloaded?

Specifically the description says Push-Pull (Trigger Action). Reference a Allen-Bradley #800FM-LMP44

I need a 22mm E-Stop PB that is maintained in both postions. Prefer NOT to have the springloaded action. Pushing it in to stop (maintained), pull it out to start.

Eric Nelson · May 23, 2013

I think "trigger action" simply means that you can't 'tease' the contacts open by pressing it slightly. When you push it past a certain point, it 'snaps' to the fully down position. The push-pull description should mean it is maintained, and will operate the way you want.

-Eric

dmargineau · May 23, 2013

http://raise.rockwellautomation.com/RAConfig/browsecatalog.asp?KW=800f+push+buttons&PID=&DLID=ABStdData&LID=ABStdProds%2CEncompass&locID=USA&onKil=browsecatalog.asp%3FLID%3DABStdProds%2CEncompass%26DLID%3DABStdData%26KW%3D800f+push+buttons%26HKW%3D%26locID%3DUSA

Ken Roach · May 23, 2013

I'm about 90% sure the 800FM-LMP44 is what you describe: a two-position maintained pushbutton where the operator is pulled straight back to the 'unpressed' position.

Most Allen-Bradley distributors have at least one standard industrial control specialist; he will be able to get you an exact and certain answer.

If this is actually an E-Stop button, in general remember that you cannot build the machine to start or even to auto-reset the E-Stop circuit as soon as the E-Stop is returned to the un-pressed position. I always use a separate momentary pushbutton to reset the emergency stop circuit.

dogleg43 · May 23, 2013

dmargineau said:
http://raise.rockwellautomation.com...ABStdData&KW=800f+push+buttons&HKW=&locID=USA

Thanks for the link.
Looks like this is a 3-position, so it does have that spring action pull out effect.

dogleg43 · May 23, 2013

Ken Roach said:
I'm about 90% sure the 800FM-LMP44 is what you describe: a two-position maintained pushbutton where the operator is pulled straight back to the 'unpressed' position.

Most Allen-Bradley distributors have at least one standard industrial control specialist; he will be able to get you an exact and certain answer.

If this is actually an E-Stop button, in general remember that you cannot build the machine to start or even to auto-reset the E-Stop circuit as soon as the E-Stop is returned to the un-pressed position. I always use a separate momentary pushbutton to reset the emergency stop circuit.

Ken,
Thanks for the reply and good info. I emailed my AB salesperson but you guys are faster.

BTW, yes there will be a separate "Power On" PB. That's why I do not want this trigger action. If there is not a simple maintained push-pull I may have to go to a twist-to-release.

Don't really care for them because sometimes brushing up against them causes a reset. Oh, well.

thanks again.

Eric Nelson · May 23, 2013

In the link posted, click on the 800F Push-Pull/Twist to Release, Illuminated (or Non-Illuminated) link.

In the 'Operator Type' selection, as long as you choose one of the Push-Pull options, you will get you the type of E-Stop button you're looking for.

I prefer the 'twist-to-release' myself. This prevents those 'stronger' people from ripping off the top of the operator when trying to release an E-stop that's already released...

-Eric

OkiePC · May 25, 2013

dogleg43 said:
If there is not a simple maintained push-pull...

There is.
You want one that will also fail open of the contact block becomes loosened from the operator, I am not sure if this applies to 22mm
I would have been puzzled by "trigger action" too. I have not seen that term used before.

Lancie1 · May 25, 2013

I would have been puzzled by "trigger action" too. I have not seen that term used before.

I suppose someone is trying to relate a Push-Pull E-Stop to pulling the trigger on a gun: before you push it (trigger it), you better make sure that you are ready for the results, and once triggered, it is hard to undo and return everything to exactly as before.

dogleg43 · May 25, 2013

Lancie1 said:
I suppose someone is trying to relate a Push-Pull E-Stop to pulling the trigger on a gun: before you push it (trigger it), you better make sure that you are ready for the results, and once triggered, it is hard to undo and return everything to exactly as before.

Lancie,
I'm just guessing, I don't think the "trigger" pertains to pushing it in. I THINK it means it is actually a 3-position switch, spring loaded to return to the middle position:
Position 1-->Pushed in (maintained in)
Position 2 -->Pulled out to center (middle position, maintained)
Position 3 -->Pulled out to outer position (springloaded, it returns to Position 2 when released.

Here's the response from my AB distributor salesperson:
"The “trigger action” you mentioned is the description for most of the E-stops AB makes and describes the snapping or returning to original position of the button. "

I gave up and just ordered a twistlock unit.

Thanks for your answers.

Lancie1 · May 25, 2013

That may be. If so, it is not a very good analogy. Most triggers that I have seen (including gun triggers) only have two positions, normal unpulled, and pulled. Adding a 3rd position and calling it a trigger is a little bit confusing to an English-speaker.

"...describes the snapping or returning to original position of the button" does sound like a trigger (which makes a snapping sound then spring-returns to its original position after being pulled). That has nothing to do with the number of positions however.

Geospark · May 25, 2013

dogleg43 said:
Does anyone know what "trigger action" would mean on an
Allen-Bradley E-Stop button?

Is this where to reset it you pull out on it and it's springloaded?

Specifically the description says Push-Pull (Trigger Action). Reference a Allen-Bradley #800FM-LMP44

I need a 22mm E-Stop PB that is maintained in both postions. Prefer NOT to have the springloaded action. Pushing it in to stop (maintained), pull it out to start.

I think were getting into this term "Trigger Action" a little too deeply? There is no great mystery to it.

It merely refers to the "type of action used" to activate and reset the push buttons.

dogleg43 said:
...That's why I do not want this trigger action...

They all use a Trigger Action of one sort or another.

The 2-position type all use a Push-To-Activate, latching, and maintained, that's a given. That's why they only refer to the resetting "Trigger Action" as "Twist-To-Release" or "Push-Pull".

You don't want Spring-To-Release in your Trigger Action, so yes , an 800FM-LMP44 Push-Pull type will give you a maintained, non spring release Trigger Action emergency stop push button.

G.

accurassay · Jan 28, 2015

A standard operator (ie: button) can be depressed enough to open or "tease" a normally closed contact to the open position momentarily without latching into the depressed position which can cause all kinds of problems. The trigger action units have a spring loaded mechanism that doesn`t depress the internal actuator that makes contact with the switch levers until AFTER the operator latches into the fully depressed position.

jdbrandt · Jan 28, 2015

Ken Roach said:
I'm about 90% sure the 800FM-LMP44 is what you describe: a two-position maintained pushbutton where the operator is pulled straight back to the 'unpressed' position.

Most Allen-Bradley distributors have at least one standard industrial control specialist; he will be able to get you an exact and certain answer.

If this is actually an E-Stop button, in general remember that you cannot build the machine to start or even to auto-reset the E-Stop circuit as soon as the E-Stop is returned to the un-pressed position. I always use a separate momentary pushbutton to reset the emergency stop circuit.

Nice side note, Ken. I see this mistake on nearly every machine I see as I travel around.
Breaks my heart - but makes me happy that it isn't my design.

E-Stop PB with "Trigger Action"

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