You Know You Are Old When

[WinterDeere]

Yep, we had one in our shop back in the 70s. We salvaged it out of a gas station we demolished a few years before. The air valve shown pressurized a tank of oil that pressurized the big hydraulic cylinder on the lift.

There's usually an air-driven hydrualic pump, in these setups, as 100 PSI in any hydraulic cylinder of reasonable size is not going to lift a car.

Air driven hydraulic pumps work by having a piston with an "air side" and a "hydraulic side", where the bore in the air side is many times larger than the hydraulic side. Think of it as two pistons with their rods tied together, a big one for air and small one for hydraulic oil, with the ratio of their cross-secions (A = pi*r^2) being the pressure multiplier. There are some valves on the associated inlets and outlets that cause the whole rig to cycle like any reciprocating piston engine, delivering flow at the desired pressure on each stroke.

 

[BravoXray]

There's usually an air-driven hydrualic pump, in these setups, as 100 PSI in any hydraulic cylinder of reasonable size is not going to lift a car.

Air driven hydraulic pumps work by having a piston with an "air side" and a "hydraulic side", where the bore in the air side is many times larger than the hydraulic side. Think of it as two pistons with their rods tied together, a big one for air and small one for hydraulic oil, with the ratio of their cross-secions (A = pi*r^2) being the pressure multiplier. There are some valves on the associated inlets and outlets that cause the whole rig to cycle like any reciprocating piston engine, delivering flow at the desired pressure on each stroke.

The one we had didn't have a hydraulic pump, only an oil reservoir pressurized by air. I helped remove the lift from the gas station site, and remember that the main lift cylinder was large, at least 18" in diameter. I was also there when we dug the hole, put forms around it, then poured concrete around it.
If you do the math, an 18" piston at 100 PSI gives you over 25,000 LBS of force, far more than needed to lift any car or pickup at the time. The shaft that came out of the floor was about 12" in diameter, and had an H shaped lift frame made of 4" I-beams. We fabricated slides that rode on the I-beams that were placed under axles or lift points to raise the vehicle. It had no safety latch to keep the lift from leaking down, so we made a couple of different lengths of 4" diameter pipe to place under the lift frame next to the lift shaft to hold it up. The bad part of using it was that we set the lift frame into the floor, so when it was raised, you had to contend with the trenches in the floor where it sat when retracted. It was really handy when removing the belly pans under dozers and earthmovers to clean them out or perform maintenance.
You did have to keep the load on it pretty much centered or it tended bind up due to the side loading.

 

[MossRoad]

This little service station is still on the corner of LaPorte and Walnut in South Bend. As I recall, it was owned by a man named Steve Starzinski. (think that was the name on it). It had a gas pump out front and to the right of the building as you faced it they had a single post hydraulic lift outside. I still remember seeing a guy standing under it working on cars, winter, summer, didn't matter. You can still make out the concrete tracks where it set into (if you use your imagination )

 

[WinterDeere]