tractor seat suspension

[serbring]

I'm thinking about farm tractor seat suspension in which there isn't axle suspensions and the unsuspended mass is much higher than the suspendend mass. Can the seat oscillation is lower than tractor one?

[Danger]

With apologies, I can't quite understand what you're asking.
If you want to know how to use the lightest possible suspended components, I'd recommend a canvas or plastic sling seat hung on bungee cords.
I somehow suspect that I'm misinterpreting you, though.

edit: Oh, crap! I just realized what you mean. There should some theoretical method of achieving what you want, but I don't know if it's physically possible. The mechanical equivalent of a sound-cancellation system is indicated, if I'm not mistaken. I'm sure that it could be done if you have access to the sort of equipment used in modern fighter aircraft flight control systems, but that's a bit out of reach for the average farmer.

[serbring]

With apologies, I can't quite understand what you're asking.
If you want to know how to use the lightest possible suspended components, I'd recommend a canvas or plastic sling seat hung on bungee cords.
I somehow suspect that I'm misinterpreting you, though.

edit: Oh, crap! I just realized what you mean. There should some theoretical method of achieving what you want, but I don't know if it's physically possible. The mechanical equivalent of a sound-cancellation system is indicated, if I'm not mistaken. I'm sure that it could be done if you have access to the sort of equipment used in modern fighter aircraft flight control systems, but that's a bit out of reach for the average farmer.

I have thought since a tractor seat has a scissor linkage, like the third in the second row, but in the past the other mechanisms was used:

http://img840.imageshack.us/f/seatc.jpg/

With the scissor system, the seat is moved only in the vertical direction while a tractor can move in all directions, do you think the system can works because is decoupled? If the tractor has a true heave motion, does the seat has a lower oscillation than the tractor frame?

[Danger]

I don't see any functional difference between #3 and #4 in that picture, but I would personally prefer either to the alternatives.
The last time that I drove a tractor, the seat was welded to the end of a leaf spring.

[serbring]

I don't see any functional difference between #3 and #4 in that picture, but I would personally prefer either to the alternatives.
The last time that I drove a tractor, the seat was welded to the end of a leaf spring.

It changes only a little bit. I think the tractor you have used is very old almost 40 years old.
However I don't know if I have explained properly my question, let me know if further explanation are necessary.

[Danger]

I think the tractor you have used is very old almost 40 years old.
More like 65 or 70. I started driving it in 1960 and it was already old even then.
I don't think that there's anything wrong with your explanation; I just don't know the answer. What I meant by the "sound-cancellation" remark is that you might require some sort of "active" movement negation system as opposed to a "passive" one.

[serbring]

More like 65 or 70. I started driving it in 1960 and it was already old even then.
I don't think that there's anything wrong with your explanation; I just don't know the answer. What I meant by the "sound-cancellation" remark is that you might require some sort of "active" movement negation system as opposed to a "passive" one.

there is just an active seat, but it works only in the vertical direction, but I think also the other direction influence strongly the vibration an the seat

[Danger]

I agree with your point. The vertical movement of the seat is not nearly as stressful and irritating as the side-to-side to-and-fro jouncing while bounding over frozen ruts in the mud.