Floor Jack Q: How does Rapid Pump/Magic Lift work?

[asm]

Hi,

Does any one know how does Rapid pump/magic lift floor jack works? Using the example below, it would seems the "plunger" drives the same volume of fluid each time. How is it possible that main cylinder extended 3 or times as fast.

Thanks

http://www.shinnfuamerica.com/Temp/2352.PDF

 

[Hiball]

On that particular model it utilizes a small tube that is centered inside the cylinder, this tube runs the length of the Ram when inserted into the bore. When the Jack is at rest and operated, oil is initially directed into this tube and since it is has a much smaller bore size it quickly raises the cylinder, meanwhile the vacuum created by ram seal raising pulls oil into the main cylinder. Once the lift arm reaches a load/resistance the adjustable speed valve seat lifts to redirect pump piston pressure into the power valve system. Im not a big fan of the "single pump" magic lift/speedy lift systems, IMO they have too many working parts, this more headaches. It seems that a lot of the import manufactures are ditching the single pump systems in favor of the twin pumps with a speed piston that has a larger displacement bore that also cuts out when the load/resistance is met.

 

[asm]

Thanks for Hiball. I think this picture I found on the Google Patent site may be the same technology. And, you are right, I have one of those jack in my garage now that can no longer "rapid pump". I guess is, the adjustable speed valve is stuck in open position. Or, it is possible that the seal around the small inner tube is blown.