JRB couplers and big buckets

[JimBruce42]

Hey all,

I have a question for everyone who has some experiences with JRB pin couplers, I'll try to set this up the best I can.

At work we have mostly Cat excavators with their own quick couplers, but on our Komatsu PC228's we have JRB's. I've had a 48" bucket on for the last week or so and when I try to switch out or just take it off, the coupler seems to not want to "let go" of the bucket without shaking the bucket a bit. It doesn't have any problem with smaller buckets or the felco bucket, just seems to be the big 48" one. I have been greasing it so I don't think the safety latch is getting stuck. Course I can only find one grease fitting and on our Cat's there are 4, but i've looked all around it and only see the one. Am I missing any?:beatsme

This is not the first 228 that's been difficult to drop the 48" bucket off of and I mentioned it to my foreman today and he said that it usually is a little bit more stubborn than other buckets to switch out.

Has anyone else ever experience this problem? Or should I ask him to get a mechanic to look at it, or (hopefully not) am I missing a fitting:Banghead?

 

[biggixxerjim]

yeah ours is a pain, sometimes. make sure the engine is idled all the way up, suck the crowd all the way in and hold half pressure on the bucket control until the latch visibly moves. that should work

 

[Burnout]

I remember the Daewoo I ran a couple years ago was the same way with the 60" ditching bucket I had. I measured the pins up and they were 1/16th of an inch out of square so the coupler sat on the bucket a little crooked. One of the other guys cracked an ear a few months later, we re welded them back on and all was solved.

 

[CascadeScaper]

Sometimes it's like burnout says, the pins could be a little out of square. Seems we have somewhat the same issue with the Esco pin grabbers on the PC400's at work, they hang up a little as well. I haven't measured the pins on the buckets, though, but I'd start there and see if that's it. If not, it could be the coupler itself not releasing the pin. Seems that a good bounce off the ground a couple times then crowd all the way in and a little jiggle once curled up does the trick.

 

[JimBruce42]

Thanks guys,:drinkup

I'll have to check the distance on the pins, it is just weird that this is the second pc228 with a 48" bucket to give me this problem. Course now one of the other pipe crews stole the machine for a few days so I have to use their 328d, darn:notworthy

 

[CascadeScaper]

What's strange is that I had absolutely no problems today with a Hendrix pin grabber on a PC200. Didn't even have to curl in or anything. Pull the safety pin, unlock and drop. I am starting to think that some couplers are better than others. And the PC200 the coupler was on has almost 11,000 hours, so I don't believe it's a matter of having a newer coupler than the Esco's on the 400's.

 

[humboldt deere]

My JRB with a 24" bucket requires a little jiggle to come loose. I like the safety of the JRB needing to be curled in all the way to release the bucket. I have read a few reports of buckets coming loose accidentally and injuring workers below.

 

[AtlasRob]

When you have completed your release motion, eg curl up and pressurise circuit, BUT before you try and set the bucket down, visually check that the ram has retracted. My Miller hitch has senior moments or it might be the clown holding the levers I put it down to simply not pressurising the circuit for a second longer and then seem to have a tight bucket.

 

[AtlasRob]

. I have read a few reports of buckets coming loose accidentally and injuring workers below.

This past month an operator has been JAILED for 12 months following the death of a worker who was hit by a bucket that became detached and hit him.

There have been at least 4 fatalities in the UK in the past year or so due to buckets becoming detached.

 

[dayexco]

on my JRB coupler, you have to curl the stick all the way in. the front pin grab releases partly by just gravity of the top of the clamp falling away from the pin. i ALWAYS place bucket on the ground, and try it to make sure it's reclamped before i place it into use.

 

[AtlasRob]

on my JRB coupler, you have to curl the stick all the way in. the front pin grab releases partly by just gravity of the top of the clamp falling away from the pin. i ALWAYS place bucket on the ground, and try it to make sure it's reclamped before i place it into use.

That sounds very similar to the new Miller hitch. If it isnt curled right up when you activate the release it unlocks the back ram but the action blocks the front pin locking mechanism that are weighted and released by gravity.
There was one on the Zaxis duck I used when mine was down, very good but a pain if you didnt curl up and give a little shake to make sure the front pin released before activating the switch.

 

[JimBruce42]

i ALWAYS place bucket on the ground, and try it to make sure it's reclamped before i place it into use.

We do that at work too, it is a "mandatory" part of the procedure to switch buckets. May even be an OSHA rule now, not sure though:beatsme

 

[LowBoy]

A bucket coming undone is a scary thought. I was on a couple Volvo's a few months back. A 290 and a 460 both with quick detach. The 290's coupler and pins were so severely worn from the shims on the bucket being broken and not replaced, there was at least a 1/2 inch space worn between the coupler and bucket pin. It was also an ugly sounding deal to run...you couldn't keep it from constantly banging around all day.
I made it a point to ALWAYS take the extra time to ensure that lock mechanism was locked. The though of a bucket hanging over those laborers heads as I'm sprinkling stone over a wall was bad enough, let alone it coming off.
In safety sensative situations like that, it's a given to G.O.A.L...Get Out And Look.

 

[AtlasRob]

Semi & Fully Hyd Hitches

The problem that has been highlighted in the UK is with semi automatic hitches.

Manual quick hitches, where you get out and release the bucket with a bar, generally on mini and some midi size diggers, OK

Fully auto hitches where you dont have to get out of the cab, have a set of weights as a safety lock that require the bucket and dipper to be pulled ( curled ) right in before activation of the switch, seem OK

Semi automatic hitches have a safety pin that has to be removed before the hitch will unlock. Our Heath & Safety Executive are attempting to get European legislation changed to ban the manufacture and supply of these type of hitches as they seem to be the ones most commonly involved with the accidents that have occured and it has been shown the operator had not fitted the safty pin.
Several UK manufactures have already ceased production of these type of hitch and are only supplying old stock.
From personal experience I know a blown hyd pipe to my hitch will not allow the hitch to release, I lost boom lift but the hitch didnt release. I know of another machine that severed a hitch supply pipe when he caught the top of his dipper arm under a bridge and the bucket did not and would not release.( we tested it )
But I have also witnessed a 20t exc drop its bucket when the in cab switch got knocked accidently. I hold the switch installation at fault for not being of the locking type, but had the safety pin been inserted the bucket would not have released SO the operator is at fault.

 

[bigcatpip]

jim make sure that you grease the two zirts on the side of the q/c because that sometime get over look. or your little flapper in the front is wornout