FEL bucket attachment

[schmism]

So i noticed that within the past "few" years most bucket design has gone from one were the bucket was mounted directly to the arm and the curl cylinder, to one that had "extra" linkage connected to the curl cylinder.

is there some mechanical advantage thats gained? or do they get away with useing a smaller curl cylinder this way?

what gives?

vs

 

[OrangeGuy]

The parallel linkage provides two advantages; 1) it gives the bucket cylinder more leverage for breakout work and backdragging, and 2) it eliminates the pinch point created when the bucket cylinder rod is attached directly to the bucket. With the bucket cylinder rod attached directly to the bucket, material (especially small stones) can spill over the bucket and "pinch" between the rod surface and the bucket causing damage to the rod which eventually damages the seals in the cylinder causing them to leak.

Generally economy built loaders use the direct connect while a high quality loader will use the parallel linkage.

I hope this answers your question.

OrangeGuy

 

[EquipmentJunkie]

Generally, the industry uses the term "4-bar linkage' to describe the additional linkage between the bucket and the loader arms.

Actually, 4-bar linkage works because it is non-parallel linkage. The distance from the dump cylinder to the pivot on the loader is greater than the distance from the top and bottom holes on the bucket. This yields two performance gains:
1. Greater breakout force
2. Additional rollback and dump for the bucket.

Like OrangeGuy said the end of the bucket cylinder is also further away from items which can cause harm to the cylinder rod and seals.

 

[N80]

I have a Kubota L4400, which is an economy model, and it does not have the 4-bar linkage and because of that the bucket does not roll back very far. With the loader arms in a low position the bucket is tilted forward and it is easy to spill stuff. To get the edges of the bucket level with the ground you have to lift the bucket above the hood line. That's no big deal unless you are on uneven ground which makes the tractor less stable.

I'm very fond of the L4400 but not being able to roll the bucket back a little further is a drawback.

 

[Soundguy]

So i noticed that within the past "few" years most bucket design has gone from one were the bucket was mounted directly to the arm and the curl cylinder, to one that had "extra" linkage connected to the curl cylinder.

If by 'few years'.. you mean about 50.. then yeah.. here is a pic of my 55 ford 660 with ford 722 1-arm loader...

Soundguy

 

[schmism]

not EXACTLY the same FEL design

 

[Soundguy]

Not the same fel design.. however.. since we were talking about the method of curling, that is.. direct bucket attachment.. or attached thru scissor bars.. well then.. As you can see.. back in the 50's the scissor bar setup was used.. so it's not like it was some 'new' idea in the last few years..

That's what i was trying to illustrate.

Soundguy

 

[N80]

Both of my B-I-L's Deeres have the 4 bar linkage and they are both from about the mid 1970's.

 

[Gig]

Generally, the industry uses the term "4-bar linkage' to describe the additional linkage between the bucket and the loader arms.

Actually, 4-bar linkage works because it is non-parallel linkage. The distance from the dump cylinder to the pivot on the loader is greater than the distance from the top and bottom holes on the bucket. This yields two performance gains:
1. Greater breakout force
2. Additional rollback and dump for the bucket.

Like OrangeGuy said the end of the bucket cylinder is also further away from items which can cause harm to the cylinder rod and seals.

The linkage only provides greater curl and dump. Breakout force is reduced because of the reduced lever arm from the bucket pivot point to the point where force is applied.

 

[JerryG]

The four-link design seems to have started in the compacts because of competition. At one time, all most all four-link loaders were industrial. Then the design went to larger Ag tractors. Now we have it on several compacts. If one company starts using a design that promotes sales, the rest will follow. I am sure that most have held off as long as possible, because it adds cost to the loader.

 

[N80]

It _looks_ like it would be weaker than the regular design, but I'm sure appearances are deceiving.

 

[EquipmentJunkie]

Gig, you are correct. The 4-bar linkage actually reduces breakout force.

I guess my brain became inverted when looking at that photo of the Kubota loader...it seemed to make sense at the time. That's why I am not an engineer.

 

[Gig]

EquipmentJunkie,
I found out to day at work that I was not totally correct, the four bar linkage does increase in force at the dump end of travel. The extra force at the dump end is not much use in an FEL but it is when the 4 bar linkage is on the back side of a backhoe or excavator bucket.

Wish my FEL had the 4 bar linkage.

 

[3RRL]

So Gig,
You are saying breakout force is reduced but dump force (on fel) is increased?
Couldn't the linkage be modified (move linkage points) to produce opposite effect desirable for greater breakout force? Just asking...

 

[Soundguy]

I would imagine, that due to the linkage, if you set it up so that the breakout made less 'movement' than the cyl throw.. then this would be mechanical advantage, and thus stronger.. and if the dump made more movement than the cyl throw.. then this would be a disadvantage, and weaker.. etc.

So yes.. I -think- what you are saying is correct.. that is.. you could adjust the linkage to make it work like that....I'm a CE.. not a ME.. but it sounds correct...

Soundguy

 

[schmism]

is there some mechanical advantage thats gained? or do they get away with useing a smaller curl cylinder this way?

well being the ME i recognized the significance of either desgin of the linkage (which is why i asked)...

ie you could use a shorter cyliner to accompish the same movement of the bucket (at a sacrafice of availibe force) (but decreased cost?)

at the same time (if designed the other way) the linkage could provide a mechanical advanage = less movement but more force.

i suppose the follow up question would be (as some have indicated) can we "handy" types convert to a linkage setup should we choose that design? (without changing entire FEL's)

oh and i see another great right up and mod being done by 3RRL

 

[3RRL]

...i suppose the follow up question would be (as some have indicated) can we "handy" types convert to a linkage setup should we choose that design? (without changing entire FEL's)

oh and i see another great right up and mod being done by 3RRL

LOL...Your turn schmism...

 

[Gig]

So Gig,
You are saying breakout force is reduced but dump force (on fel) is increased?
Couldn't the linkage be modified (move linkage points) to produce opposite effect desirable for greater breakout force? Just asking...

Well dump force is only increased toward the end of the dump travel. During the mid range of the buckets rotation you have less force because of the trade off to more rotation angle.

I am a newbie to the tractor/FEL world so my defn. of breakout force may be off. Breakout force is the max force the bucket can exert at the bucket cutting edge in the curl direction????

SoundGuy is right, all other things being equal, if you increase rotational travel you decrease "breakout force", and decreasing rotational travel increases "breakout force". To get both = bigger cylinder + $$