Our newest machine has a logic problem. The machine has two nail guns that
assemble a handle onto a wooden block brush. The operator loads a handle
and brush into the fixture and presses two palm switches. The palm switches
energize a relay that latches and energizes the solenoid valve that controls
an air cylinder that lifts the fixture to the nail guns until the fixture
hits a limit switch. The NC contacts on the limit switch then open and the
relay unlatches. The NO contacts close and energize a solenoid valve that
supplies air to the triggers on the nail guns. (There is also a limit switch
at the bottom of the stroke that powers the palm switches only at the bottom
position.)

The problem is that when the fixture hits the limit switch it reverses
direction immediately. The gun trigger air solenoid only gets that quick
hit and doesn't have enough time to build up enough pressure to trigger the
guns. I need to delay the fixture at the top of the stroke long enough to
fire the guns.

A few tenths of a second should be enough. An off-delay timed relay should
do it, right? As I look through the Grainger catalog and McMaster-Carr I
get a bit confused.

What is a "Off delay Retrigerable, one shot" relay? I don't think that this
is what I want but I'm not sure. I think I want just an "Off Delay" relay.

On Wed, 14 Nov 2007 12:33:41 -0500, "Tom Gardner"
wrote:

Our newest machine has a logic problem. The machine has two nail guns that
assemble a handle onto a wooden block brush. The operator loads a handle
and brush into the fixture and presses two palm switches. The palm switches
energize a relay that latches and energizes the solenoid valve that controls
an air cylinder that lifts the fixture to the nail guns until the fixture
hits a limit switch. The NC contacts on the limit switch then open and the
relay unlatches. The NO contacts close and energize a solenoid valve that
supplies air to the triggers on the nail guns. (There is also a limit switch
at the bottom of the stroke that powers the palm switches only at the bottom
position.)

The problem is that when the fixture hits the limit switch it reverses
direction immediately. The gun trigger air solenoid only gets that quick
hit and doesn't have enough time to build up enough pressure to trigger the
guns. I need to delay the fixture at the top of the stroke long enough to
fire the guns.

A few tenths of a second should be enough. An off-delay timed relay should
do it, right? As I look through the Grainger catalog and McMaster-Carr I
get a bit confused.

What is a "Off delay Retrigerable, one shot" relay? I don't think that this
is what I want but I'm not sure. I think I want just an "Off Delay" relay.

Hey Tom,

Always a problem to get anything electronic to "delay" AFTER the power
is removed. But an air-check armature type will. I have a handful of
Allen-Bradley 115 VAC, if you want to give me a snail-mail and you can
wait long enough for them to get there, they will be free.

I think if it was me, I'd be leaving the air on to the nail-guns and
setting the nail guns to "bump-fire".

Take care.

Brian Lawson,
Bothwell, Ontario.

On Nov 14, 9:33 am, "Tom Gardner" wrote:
Our newest machine has a logic problem. The machine has two nail guns that
assemble a handle onto a wooden block brush. The operator loads a handle
and brush into the fixture and presses two palm switches. The palm switches
energize a relay that latches and energizes the solenoid valve that controls
an air cylinder that lifts the fixture to the nail guns until the fixture
hits a limit switch. The NC contacts on the limit switch then open and the
relay unlatches. The NO contacts close and energize a solenoid valve that
supplies air to the triggers on the nail guns. (There is also a limit switch
at the bottom of the stroke that powers the palm switches only at the bottom
position.)

The problem is that when the fixture hits the limit switch it reverses
direction immediately. The gun trigger air solenoid only gets that quick
hit and doesn't have enough time to build up enough pressure to trigger the
guns. I need to delay the fixture at the top of the stroke long enough to
fire the guns.

A few tenths of a second should be enough. An off-delay timed relay should
do it, right? As I look through the Grainger catalog and McMaster-Carr I
get a bit confused.

What is a "Off delay Retrigerable, one shot" relay? I don't think that this
is what I want but I'm not sure. I think I want just an "Off Delay" relay.

Some guns we used, notably Bostich, were very slow to respond.
If a customer felt it was in their best interest to stay with the
Bostich
we would add a small poppet valve right on the gun, and just use
the brief trigger pulse to fire the valve which fired the gun; this
was
much more reliable. When using other guns we always made sure
the firing valve was as close to the gun as possible (1 to 2 feet) and
this was always enough to get fast firing times (while the guns were
in motion by the way). The small poppet valve was a Humphry and
supplied by Bostich. The main firing valves we used were ARO 3/8".

Although you don't mention specifics, another idea Engineering came
up with was to use a coil of vinyl tubing before the item you wanted
to delay the return of. The idea was to delay the movement of the
cylinder until the entire coil/reservoir/cylinder pressure had dropped
sufficently to allow the assembly to move. It worked fairly well in
non-critical applications.

Good luck.

dennis
in nca

"Brian Lawson" wrote in message
...
On Wed, 14 Nov 2007 12:33:41 -0500, "Tom Gardner"
wrote:

Our newest machine has a logic problem. The machine has two nail guns
that
assemble a handle onto a wooden block brush. The operator loads a handle
and brush into the fixture and presses two palm switches. The palm
switches
energize a relay that latches and energizes the solenoid valve that
controls
an air cylinder that lifts the fixture to the nail guns until the fixture
hits a limit switch. The NC contacts on the limit switch then open and
the
relay unlatches. The NO contacts close and energize a solenoid valve that
supplies air to the triggers on the nail guns. (There is also a limit
switch
at the bottom of the stroke that powers the palm switches only at the
bottom
position.)

The problem is that when the fixture hits the limit switch it reverses
direction immediately. The gun trigger air solenoid only gets that quick
hit and doesn't have enough time to build up enough pressure to trigger
the
guns. I need to delay the fixture at the top of the stroke long enough to
fire the guns.

A few tenths of a second should be enough. An off-delay timed relay
should
do it, right? As I look through the Grainger catalog and McMaster-Carr I
get a bit confused.

What is a "Off delay Retrigerable, one shot" relay? I don't think that
this
is what I want but I'm not sure. I think I want just an "Off Delay"
relay.

Hey Tom,

Always a problem to get anything electronic to "delay" AFTER the power
is removed. But an air-check armature type will. I have a handful of
Allen-Bradley 115 VAC, if you want to give me a snail-mail and you can
wait long enough for them to get there, they will be free.

I think if it was me, I'd be leaving the air on to the nail-guns and
setting the nail guns to "bump-fire".

Take care.

Brian Lawson,
Bothwell, Ontario.

Thanks, I graciously accept your offer and will gladly trade you some
brushes. I can't bump-fire as we have eliminated the safeties and modified
the noses to fit in between rows of wire.
see: http://www.ohiobrush.com for an address. I'll need yours.

If it were me, I would parallel the NC contacts on the limit
switch with a set of NC contacts on a pressure switch that
senses the pressure on the triggers. Your holding relay
would then not drop out until you achieve full pressure on
the trigger line. This setting can be set high enough so
that the trigger operates before this setting is reached
thus giving you a delay. If needed, you could put a
restricter in the line to the pressure switch to tune the
timing.

On Wed, 14 Nov 2007 12:33:41 -0500, "Tom Gardner" wrote:

Our newest machine has a logic problem. The machine has two nail guns that
assemble a handle onto a wooden block brush. The operator loads a handle
and brush into the fixture and presses two palm switches. The palm switches
energize a relay that latches and energizes the solenoid valve that controls
an air cylinder that lifts the fixture to the nail guns until the fixture
hits a limit switch. The NC contacts on the limit switch then open and the
relay unlatches. The NO contacts close and energize a solenoid valve that
supplies air to the triggers on the nail guns. (There is also a limit switch
at the bottom of the stroke that powers the palm switches only at the bottom
position.)

The problem is that when the fixture hits the limit switch it reverses
direction immediately. The gun trigger air solenoid only gets that quick
hit and doesn't have enough time to build up enough pressure to trigger the
guns. I need to delay the fixture at the top of the stroke long enough to
fire the guns.

A few tenths of a second should be enough. An off-delay timed relay should
do it, right? As I look through the Grainger catalog and McMaster-Carr I
get a bit confused.

What is a "Off delay Retrigerable, one shot" relay? I don't think that this
is what I want but I'm not sure. I think I want just an "Off Delay" relay.

Trying to wrap my mind around the difference between on and off delay
here, but just happened to be looking up this little beast for my work
today.
http://www.marshbellofram.com/ATC/339A_series.htm

Other than being the opposite 'on-ness' think it is about what your
looking for. A local supplier claims to have them in stock for around
$32.

We have a small automatic router that was built in house years ago and
uses several of these timers. (Simply cuts a rectangular hole in the top
of small plastic boxes) Yours truly been tasked with building a new
one... Hopefully a bit less kludgie than the original

The old timers have held up well despite the rough treatment they have
received so I plan on using the closest one still available in that
series.
--
William

Ron wrote in :

If it were me, I would parallel the NC contacts on the limit
switch with a set of NC contacts on a pressure switch that
senses the pressure on the triggers. Your holding relay
would then not drop out until you achieve full pressure on
the trigger line. This setting can be set high enough so
that the trigger operates before this setting is reached
thus giving you a delay. If needed, you could put a
restricter in the line to the pressure switch to tune the
timing.


That was also my thought on a solution to the problem.


--
Anthony

You can't 'idiot proof' anything....every time you try, they just make
better idiots.

Remove sp to reply via email

On Nov 14, 9:33 am, "Tom Gardner" wrote:
Our newest machine has a logic problem. The machine has two nail guns that
assemble a handle onto a wooden block brush. The operator loads a handle
and brush into the fixture and presses two palm switches. The palm switches
energize a relay that latches and energizes the solenoid valve that controls
an air cylinder that lifts the fixture to the nail guns until the fixture
hits a limit switch. The NC contacts on the limit switch then open and the
relay unlatches. The NO contacts close and energize a solenoid valve that
supplies air to the triggers on the nail guns. (There is also a limit switch
at the bottom of the stroke that powers the palm switches only at the bottom
position.)

The problem is that when the fixture hits the limit switch it reverses
direction immediately. The gun trigger air solenoid only gets that quick
hit and doesn't have enough time to build up enough pressure to trigger the
guns. I need to delay the fixture at the top of the stroke long enough to
fire the guns.

A few tenths of a second should be enough. An off-delay timed relay should
do it, right? As I look through the Grainger catalog and McMaster-Carr I
get a bit confused.

What is a "Off delay Retrigerable, one shot" relay? I don't think that this
is what I want but I'm not sure. I think I want just an "Off Delay" relay.



Use a spring to push the trigger for a longer push or use a flow
control valve in the push side of the cly for slower action...

Tom Gardner wrote:
Our newest machine has a logic problem. The machine has two nail guns that
assemble a handle onto a wooden block brush. The operator loads a handle
and brush into the fixture and presses two palm switches. The palm switches
energize a relay that latches and energizes the solenoid valve that controls
an air cylinder that lifts the fixture to the nail guns until the fixture
hits a limit switch. The NC contacts on the limit switch then open and the
relay unlatches. The NO contacts close and energize a solenoid valve that
supplies air to the triggers on the nail guns. (There is also a limit switch
at the bottom of the stroke that powers the palm switches only at the bottom
position.)

The problem is that when the fixture hits the limit switch it reverses
direction immediately. The gun trigger air solenoid only gets that quick
hit and doesn't have enough time to build up enough pressure to trigger the
guns. I need to delay the fixture at the top of the stroke long enough to
fire the guns.

A few tenths of a second should be enough. An off-delay timed relay should
do it, right? As I look through the Grainger catalog and McMaster-Carr I
get a bit confused.

What is a "Off delay Retrigerable, one shot" relay? I don't think that this
is what I want but I'm not sure. I think I want just an "Off Delay" relay.



Yes, an off delay would do the job, I read Off delay, retriggerable,
one shot to mean: after the trigger is removed, the relay waits a
period before releasing, this period can be reset by supplying a pulse
to the relay before it has reached off time, and one shot means the
relay only needs a pulse, not a continuous trigger.

Other options might include using a limit with a long flexible stick to
trigger the air guns just before the lift tops out, thereby letting the
last tenth of a second of lifting be your delay. Or triggering the down
action by a pressure switch triggered by the exhaust port of the nail
guns, thus ensuring that the guns have cycled before letting the
completed assembly down.

Stuart

On Nov 14, 7:03 pm, Stuart Wheaton wrote:
Tom Gardner wrote:
Our newest machine has a logic problem. The machine has two nail guns that
assemble a handle onto a wooden block brush. The operator loads a handle
and brush into the fixture and presses two palm switches. The palm switches
energize a relay that latches and energizes the solenoid valve that controls
an air cylinder that lifts the fixture to the nail guns until the fixture
hits a limit switch. The NC contacts on the limit switch then open and the
relay unlatches. The NO contacts close and energize a solenoid valve that
supplies air to the triggers on the nail guns. (There is also a limit switch
at the bottom of the stroke that powers the palm switches only at the bottom
position.)

The problem is that when the fixture hits the limit switch it reverses
direction immediately. The gun trigger air solenoid only gets that quick
hit and doesn't have enough time to build up enough pressure to trigger the
guns. I need to delay the fixture at the top of the stroke long enough to
fire the guns.

A few tenths of a second should be enough. An off-delay timed relay should
do it, right? As I look through the Grainger catalog and McMaster-Carr I
get a bit confused.

What is a "Off delay Retrigerable, one shot" relay? I don't think that this
is what I want but I'm not sure. I think I want just an "Off Delay" relay.

Yes, an off delay would do the job, I read Off delay, retriggerable,
one shot to mean: after the trigger is removed, the relay waits a
period before releasing, this period can be reset by supplying a pulse
to the relay before it has reached off time, and one shot means the
relay only needs a pulse, not a continuous trigger.

Other options might include using a limit with a long flexible stick to
trigger the air guns just before the lift tops out, thereby letting the
last tenth of a second of lifting be your delay. Or triggering the down
action by a pressure switch triggered by the exhaust port of the nail
guns, thus ensuring that the guns have cycled before letting the
completed assembly down.

Stuart- Hide quoted text -

- Show quoted text -

"On delay" means "Delay before turning ON"

"Off delay" means "Delay before turning OFF"

Some relays need an electrical signal to "re-set"
Some re-set themselfs.

All gun manufacturers manufacture "remote triggers"
for their guns, Many of these triggers replace the
mechanical trigger parts.
Some "remote triggers" are mounted in other pos-
itions.
All mechanical triggers I'm familiar with are dis-
abled by the installation of the "remote triggers."

Rarely I've seen "remote triggers" actually move
a mechanical part in order to fire the gun, all
others are plumbed to valving within the gun.

dennis
in nca

dennis
in nca

Hey Tom

OK. Got the street address. I'll send some. How soon do you need
them? Actually, no doubt about it, better if I send them from
Michigan late Friday or early Saturday. I have to go to a meeting for
NAMES in Ann Arbor, so it's very easy for me to get them across the
border rather then the goofing around with US Customs Forms sending
from here. So, forget I asked.

I'll box up a few and send them..how?? USPS, USPS Priority, UPS,
DHL, Fedex.........whaaaaaatttt???? Lemme know soonest.

Take care.

Brian Lawson
ps...they are free to you. I got a bunch I didn't even bid on at an
auction a week or so ago. Didn't even realize there were any of this
type in the drawers until I was sorting through all the crap I got. We
used these same ones on older elevators, so they were a surprise but
familiar type.

XXXXXXXXXXXXXXXXXXXXXXXXXXXXX

On Wed, 14 Nov 2007 14:31:38 -0500, "Tom Gardner"
wrote:


"Brian Lawson" wrote in message
.. .
On Wed, 14 Nov 2007 12:33:41 -0500, "Tom Gardner"
wrote:

Our newest machine has a logic problem. The machine has two nail guns
that
assemble a handle onto a wooden block brush. The operator loads a handle
and brush into the fixture and presses two palm switches. The palm
switches
energize a relay that latches and energizes the solenoid valve that
controls
an air cylinder that lifts the fixture to the nail guns until the fixture
hits a limit switch. The NC contacts on the limit switch then open and
the
relay unlatches. The NO contacts close and energize a solenoid valve that
supplies air to the triggers on the nail guns. (There is also a limit
switch
at the bottom of the stroke that powers the palm switches only at the
bottom
position.)

The problem is that when the fixture hits the limit switch it reverses
direction immediately. The gun trigger air solenoid only gets that quick
hit and doesn't have enough time to build up enough pressure to trigger
the
guns. I need to delay the fixture at the top of the stroke long enough to
fire the guns.

A few tenths of a second should be enough. An off-delay timed relay
should
do it, right? As I look through the Grainger catalog and McMaster-Carr I
get a bit confused.

What is a "Off delay Retrigerable, one shot" relay? I don't think that
this
is what I want but I'm not sure. I think I want just an "Off Delay"
relay.

Hey Tom,

Always a problem to get anything electronic to "delay" AFTER the power
is removed. But an air-check armature type will. I have a handful of
Allen-Bradley 115 VAC, if you want to give me a snail-mail and you can
wait long enough for them to get there, they will be free.

I think if it was me, I'd be leaving the air on to the nail-guns and
setting the nail guns to "bump-fire".

Take care.

Brian Lawson,
Bothwell, Ontario.

Thanks, I graciously accept your offer and will gladly trade you some
brushes. I can't bump-fire as we have eliminated the safeties and modified
the noses to fit in between rows of wire.
see: http://www.ohiobrush.com for an address. I'll need yours.

"Brian Lawson" wrote in message
...
Hey Tom

OK. Got the street address. I'll send some. How soon do you need
them? Actually, no doubt about it, better if I send them from
Michigan late Friday or early Saturday. I have to go to a meeting for
NAMES in Ann Arbor, so it's very easy for me to get them across the
border rather then the goofing around with US Customs Forms sending
from here. So, forget I asked.

I'll box up a few and send them..how?? USPS, USPS Priority, UPS,
DHL, Fedex.........whaaaaaatttt???? Lemme know soonest.

Take care.

Brian Lawson
ps...they are free to you. I got a bunch I didn't even bid on at an
auction a week or so ago. Didn't even realize there were any of this
type in the drawers until I was sorting through all the crap I got. We
used these same ones on older elevators, so they were a surprise but
familiar type.

XXXXXXXXXXXXXXXXXXXXXXXXXXXXX

Send me your e-mail address and I'll send you my UPS and FedEx numbers
tomorow, I forget them and I'm at home now, having a cup of shade-grown
coffee...Mmmm!

Hey Tom,

Too late. I'm off to Detroit right now, so it will be either UPS or
FedEX, depending on what office I get to first.

Brian.
XXXXXXXXXXXXXXXX

On Fri, 16 Nov 2007 03:09:14 GMT, "Tom Gardner"
wrote:


"Brian Lawson" wrote in message
.. .
Hey Tom

OK. Got the street address. I'll send some. How soon do you need
them? Actually, no doubt about it, better if I send them from
Michigan late Friday or early Saturday. I have to go to a meeting for
NAMES in Ann Arbor, so it's very easy for me to get them across the
border rather then the goofing around with US Customs Forms sending
from here. So, forget I asked.

I'll box up a few and send them..how?? USPS, USPS Priority, UPS,
DHL, Fedex.........whaaaaaatttt???? Lemme know soonest.

Take care.

Brian Lawson
ps...they are free to you. I got a bunch I didn't even bid on at an
auction a week or so ago. Didn't even realize there were any of this
type in the drawers until I was sorting through all the crap I got. We
used these same ones on older elevators, so they were a surprise but
familiar type.

XXXXXXXXXXXXXXXXXXXXXXXXXXXXX

Send me your e-mail address and I'll send you my UPS and FedEx numbers
tomorow, I forget them and I'm at home now, having a cup of shade-grown
coffee...Mmmm!

"Brian Lawson" wrote in message
...
Hey Tom,

Too late. I'm off to Detroit right now, so it will be either UPS or
FedEX, depending on what office I get to first.

Brian.
XXXXXXXXXXXXXXXX

Sorry, I didn't get in to the office until late, I'll send a check, send me
your address. THANKS!!!

According to Tom Gardner :

[ ... ]

guns. I need to delay the fixture at the top of the stroke long enough to
fire the guns.

A few tenths of a second should be enough. An off-delay timed relay should
do it, right? As I look through the Grainger catalog and McMaster-Carr I
get a bit confused.

First off -- if your relay controls are DC powered and not AC
powered, there are relays from old phone systems which would serve you
well. The normal relay has one or two coils wound on the center soft
iron core (about 3" long IIRC), and that one is quick both in pick and
in release. The ones which I am describing below were made by Automatic
Electric and Claire -- among others.

Then you take one of the two-coil ones and replace one of the
coils with a slug of copper occupying the same space. If the copper
slug is closer to the moving arm of the relay, it will be slow to pick,
and only slightly slow to release.

If the copper slug is closer to the base of the relay, then it
will be only slightly slow to pick, but quite slow to release, which is
what you want.

Ones made to be slow in both have the copper as a thick-walled
sleeve around the core with the winding around that.

Now -- there are other ways to do this. That copper slug is a
shorted turn. You can get some of the same effect (a bit less delay) by
putting a short circuit across the terminals of a second coil -- at the
base if you have a choice. And to make it still as quick pick up but
slow release, use a spare pair of contacts to short the second coil's
terminals only once the relay has actuated.

Or -- you can connect a capacitor across the coil's windings,
with a diode to isolate it from the control power when the relay turns
off. (Again, you need DC relays for this.)

Or -- get a relay with a dashpot which can either be slow to
pick or slow to release, depending on the design. Those can be DC or AC.

What is a "Off delay Retrigerable, one shot" relay? I don't think that this
is what I want but I'm not sure. I think I want just an "Off Delay" relay.

That is an electronics description of the behaviour which you
want. It will need steady power independent of the control signal. The
"one shot" is a circuit which goes through its time cycle once per input
pulse. The real question is whether it can be adjusted to turn off
quickly enough so it does not slow your production.

Good Luck,
DoN.
--
Email: | Voice (all times): (703) 938-4564
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