Rusty is on the right track......
It's all relative, the radius of the drive gear, the length of the handle, the weight on the handle end, etc.
I suspect the press rating is the maximum force that it can handle, rather than a measurement of its press power.
But - this is a simple machine, a lever. Instead of two lengths on either side of a pivot this has one length attached to a gear that transfers the force at a right angle down to the shaft. The gear is kind of the key. If the end of the handle moves 10" when the press moves 10" down the force pushing down on the handle would equal the force pressing down through the press, almost (a small amount of energy would be lost to friction and would be turned into heat, other energy could be lost bending components of the system.) The gear radius would then be the length of the input lever. The torque at the gear moves the shaft. The distance from the center of the gear to the point it applies force through the shaft is like one side of a see-saw, the other side is the point on the handle where force is applied at to the center of the gear. The center if the gear is the pivot point.
So how is the downward force applied to the handle amplified?
The travel distance of each of the points where the force is applied is needed to determine how much the force is multiplied, or rather to cslculate the ratio of input force to output force.
Moment is the force times distance. If we consider the effect of friction and energy lost flexing the bar to be negligible the input moment will equal the output moment.
Formulaicly stated the input force times the input length equals the output force times the output length.
Given an input arm length of 10" with a gear radius of 1" the ratio is 10 to 1.
A simple measurement using the picture and my finger as a ruler looks like the ratio of (handle to center of gear) to (center of gear to center of press shaft) is around 12 to 1.
Based on a 2 ton rating, and my inaccurate finger measurement, you should be able to apply 333-1/3 lbs of weight on the end of the handle safely. (Don't use this, I am guessing on the lengths.)
Measure the distance from:
A. The center of the gear to the point you pull down on the handle
and
B. The center of the gear to the center of the press shaft.
Alternatively, measure the distance the handle travels and the distance the press shaft travels. Remember to take the handle distance at the point you apply the force (about the middle of where you grab it.)
The ratio is handle distance to shaft distance.
If shaft distance is 1/2" and handle distance is 10", the ratio is (10) 20 to (1/2) 1. About 200 lbs max input then.
Long explanation for what Rusty almost said. Sorry for that.
Chilly
