Hi LD1,
let me point out that you in fact insulted me first by completely disregarding every thing i said in this statement
"Then yes it helps increase the range of travel of the bucket. Depending on how the link is designed it can also give additional force during some range of stroke"
when you said
"It dont really increase the range of travel, or the force at all. But what it does is allow a longer cylinder to be used, to gain greater travel, before the cylinder rod contacts the loader arm.
So if your cylinder is 20" long, and all other geometry being equal, a 4 bar wont give any greater travel than pinned straight to the bucket."
lets first examine these two statements "It dont really increase the range of travel" and "So if your cylinder is 20" long, and all other geometry being equal, a 4 bar wont give any greater travel than pinned straight to the bucket."
First i never explicitly said it was the sole reason for gaining more travel I only said "it helps increase the range of travel" However in this case it pretty much is the sole reason for the increase of travel. the LA1353 has a 20.2" stroke on the curl cylinder while The LA524 that goes on the L3800 has an 18.7" yet the total range of motion gained by the 4 bar linkage is far more than what an extra 1.5" of stroke would give you. 1.5" is only and 8% increase in length.
You don't need to increase the cylinder stroke to gain range of motion with a 4 Bar linkage.
I would speculate they use a longer cylinder just for the fact that loader has been scaled up with about 4 times the lift capacity and about 50% more lift height >4' an 8% increase in curl cylinder length seems miniscule
Lift Capacity (Bucket pivot pin, max height)
LA524 1131 pounds v LA1353 3990 lbs at height position.
Secondly I never implied that the linkage on this tractor improved mechanical advantage/force. As previously stated the main goal of this linkage is to increase travel which would imply that the opposite would have to be true. In fact the loader pictured decreases force significantly during the end part of the stroke. I was attempting to give a high level overview of 4 bar linkages. "Depending on how the link is designed it can also give additional force during some range of stroke" I did not go into detail but what i meant was that you could design a 4 bar to get this advantage the bolt cutter example is the proof.
My comments in bold italic to this next post
I didn't contradict myself, but maybe I wasnt clear.
Lets use my kubota for example. Its a L3800 with a curl cylinder directly pinned to the bucket. And IIRC, it uses a cylinder with a ~20" stroke.
IF, I added a cylinder of 24" stroke, I would gain curl angle/ range of travel, BUT, would get to the point where the cylinder rod hits the loader arm, so its not possible.
Exactly this is why you need a 4 bar linkage regardless of cylinder length its physically impossible to crash through the loader tube and not cause damage
IF, I added a 4-bar linkage like used on loaders, I would gain nothing in range of travel.
False - See my attached Pictures
BUT, using the 4-bar keeps the cylinder rod away from the loader arm and allows for the use of a longer cylinder.
It would but its not necessary with a 4 bar linkage design that has been optimized for a specific purpose - kubota did not need to significantly increase the cylinder size - See my attached Pictures
Bolt cutters are a totally different thing...
Agreed, they do the complete opposite just showing contrast, another great example of a 4 bar linkage in action is a windshield wiper operating mechanism but that's a whole different discussion
And lets keep it civil. No need for the digs and insults.:thumbdown:
like my brother said "He started it"
The picture of THAT 4 bar does indeed increase dumping angle, but at a decrease of force.
Thats not the typical 4-bar I see. Like on my BH and the one posted in post #5 by xring100. When the upper bar is mounted inline (same pivot) as the cylinder, there is no mechanical advantage.
The pic of that L35, the upper bar moves at a faster rate than the cylinder. If you were to reverse where the upper bar and cylinder are mounted, you would have much more force, but less range of travel.
Yep you've got this more direct approach to a 4 bar linkage The main disadvantage I see of this style is the additional height required for this linkage can obstruct view
And now for the good stuff. A Brief Photo lesson on the 4 bar linkage of the LA1353 loader
Slide One
The links are are almost parallel actually the bucket link is rotated farther back then the link attached to the cylinder
Slide TWO
Notice the ratio of the blue and yellow link lines almost 2:1 I included all the dimensions +/- 1/4" so feel free to model this
Slide Three
My favorite slide yes this one shows beyond a doubt that this 4 bar linkage definitely increase range by a factor of almost 2:1 no longer cylinder required. The overall height of the boom was changed a few inches between pictures so angles are not perfect but close enough to get the idea when i curled the bucket up my tines hit one of the rafters so i had to lower it slightly. in reality the bucket actually has more articulation angle than shown. This design has almost 180 degrees of sweep you will never approach that with a pin on style bucket
I understand you could get some additional angle out of a direct pin on cylinder with some changes to geometry. However don't get to excited it won't be this much that's what i prove with the slide 5
Slide 4 & 5
I'm guessing the kubota marketing guys didn't quite catch the full understanding of what the kubota engineering guys were telling them when they described the 4 bar linkage advantages
Enjoy
No hard feelings
