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Okay we're standing
at the take up unit of our C-250 demonstration conveyor,
and I wanted to explain
what we see here. First of all, the take-up unit consists of a fixed
section, of telescopic track, a moving section of
telescopic track which is attached to 180 degree curve,
and which is pushed outwards by
these springs. Now, when I first look at this take up unit, the first thing that
I see, is that it has been properly adjusted
in that, first of all, the shipping nut
we call them shipping nuts, they've been taken out to the end of this threaded rod.
This is important, because if these nuts were here,
this section of the telescopic track would not be able to extend,
it would be restrained. Now I can see that we can have at least
another five-inches' of travel on this side another five inches of travel on the
other side, meaning
we have plenty of take-up available as our chain
elongates over the years.
The system is relatively new I can see, because
the nut that's on this side of the spring which is used to tension this spring
here we put a, If I tighten this up this is going to cause this
side of the spring to compress and that will put more force
on the 180 degree curve
causing the chain to be pulled outside. You can
in some instances cause adverse effects by making this tight.
Too tight means you're adding chain tension where you didn't need to
and it may cause wear on your chain or it may make the drive unit
excessively dog, it will slow down.
If you look inside
the slot on this, I can see that the end of the inside
telescopic section is about here, meaning we have
a good amount of travel overall on this
this section.
At start I think it's about nine inches of travel on each side
Well why do I need that much travel ? Well
If you had an eight hundred foot long system and it got
four linkages per foot, you know you've got 3200
linkages. If they all wear at 10 thou, you've got
a significant amount of change, we call it stretch, but it's really wear, and
that's not good. So
When do you run into problems with the take-up ?
Well, When this section is either
reaching the end here.. so if this little tab has been right at the end
of this threaded rod, we'd basically be at the end of it's travel.
The next.. the only thing you can do at that point
is collapse this take up unit, you can do that by
by screwing the shipping nut back in
making it come in. Simultaneously you'd go to the nearest
track inspection section, take the cover off,
pull the chain out, and then disconnect
a section of chain. That's how you take out a foot of chain.
and then reconnected it and then
move those shipping nuts back out, and as you do the system will find its new
location, and from there
you would then use this nut, to
make this spring have the proper amount of tension
on that curve. So what's the proper amount of tension ?
Well I usually go and rotate this. .. This one could actually be a little bit tighter
so I would turn this
I can turn this nut compressing the spring a little bit more
without any problem. You never want these
spring coils to be touching each other, because that would be
that would mean that it's completely solid and you're putting excess pressure
on
the conveyor chain causing undue wear.
So something like that. I can see here by the
tension on that chain that that's pretty good.
Now, as we said, there are different situations whereby you either want this
to be tighter or looser
and one of them is a reversing chain, if you ever have a system
where you need to reverse your chain occasionally those
springs may have to be a lot tighter, because
the chain will be probably
in all cases, in any case it will be compressing this curved slightly,
you'll have to watch out for that.
In most cases as I said earlier, we want to
position the take-up unit after the drive unit
close as possible, and if there's a decline
anywhere after the drive, you usually want the
take up at the bottom or at the lowest point in the system.
Why? Because the chain with the load hanging off it
has some weight to it and it'll try to run away downhill. So it's actually gonna
naturally suck the chain out of the slot side of the
drive unit, and the take-up will be sitting there waiting
to take it out.
Okay. In the event that
your take-up unit is extended all the way,
you need to take out chain, and I just wanna show you a quick procedure for doing that.
First thing we're going to do is,.. you can do two things here.
We could either used the come along connect it to the crossbar,
take the end of this curve, and pull this in
to compress the spring again and then we're going to have
slack chain in the system, which we're gonna pull out at the nearest
inspection section and that may be at the drive, for all intensive purposes.
Or you could move these nuts
these shipping nuts in, and use them to compress the curve,
compress the spring which would move the curve in.
So that there. Spin this down.
So now I'm going to wind this in,
to the point where I get some slack, enough slack so I can take some chain
out of the take up. I may have to have a person working down there too, pulling the chain out.
while I'm doing this.
It can take a while, the take up
the come along method is what our guys use because it's faster.
Okay we've moved over to the drive unit
and the location of the nearest inspection section.
PACLINE always puts an inspection section on one side or the other of
the drive unit and normally between the
drive unit and the take-up. So where the chain will need to be removed.
So I've already removed the, locked out the unit
remove the bolt from the inspection cover.
First take this off. So you can see here
that the winding in at the take-up unit, is caused the chain to become slack
so we're able to pull this chain up and
out of this inspection section, and when we do
we can now either remove a cotter pin
from the joining rivet which
we have every ten or fifteen feet on this type of conveyor
but if not, we would simply take a grinder and grind the head of
this rivet, so that we can then
pop out this pin and take out a few
an amount of chain. It could be as little as 6 inches or
as much as 12 or 18 inches depending on how long the system is.
and when we do this have, you have to be a
careful that if our system has
minimum differences between carriers
we'll have to make sure that
we always leave a space bigger than that. So if our system has a minimum of 18 inch
spacing between carriers and we're just taking out six inches, I would
make it a 12 in space,
we would actually have to take off a whole carrier and this is important when
the carriers are going around corners where they touch, or going up and down inclines and declines.
Okay one of the
things I wanted to show you, was the effect of a slack chain, and what actually happened.
I can see with the take up unit wound in, this is a slack chain and what happens is
these chain pendant have
basically nowhere to go. They can't be
pushed closer together, they reach a certain point
they go sideways because they have sharp edges on, they actually will scratch the
track, or do something else, happens with all chains.
Once your at this point
this chain will turn sideways in the track and start scraping
they give a noise and quite often you'll see metal filings on the ground and that'll be
your
clue as to what happened here. If it gets really bad
it'll push right back into the drive unit and then you have a possibility of
the caterpillar chain drive dog,
jamming. Not a good situation. So it's a very easy procedure
always look at your take up unit first, see where the springs are, see if there's
movement available
take the chain pendant
right after the drive unit. Just go like this
This is excessive movement. Now we're gonna have the chain tightened up again,
we will show you what proper movement is. It should only move
back and forth a small amount. Okay.
So we've adjusted the take-up unit properly now, I wanna show you
how much the chain pendant should move. You can see here
I'm putting a fair amount of force on it and it's not rocking
side to side very much. So that's good.
We always want it to be that way.