How has the car jack evolved over the years?
I have an idea. Do some research and then tell US. (!)
i have tried but the internet is not as reliable as i wish
Maybe you look into the company that makes the Hi-Lift type jacks.
What basic design did the early jacks have? screw,rachet,hydraulic.lever?
If you mean the jacks the average motorist uses to change a tire (as opposed to service jacks), the answer is very little. Except for a few oddball cars here and there that use hydraulic bottle-jacks, since they started coming with jacks almost every car has come with some variation of a little platform that moves up and down a threaded shaft. Back when cars had bumpers, most of them had bumper jacks which were tall awkward things you had to wedge between your bumper and the ground and cross your fingers that the thing doesn’t slip off the bumper or that the bumper itself doesn’t break off, which was a pretty common occurrence in the rust belt! Some time in the 70’s (I think) they started using scissors jacks which work on basically the same concept, but are more compact and stable and are basically what most cars come with today.
Well, years ago most US cars came with bumper jacks, dangerous, nasty ratcheting devices that fit between a car’s bumper (chrome, of course) and the ground. You were lucky if you didn’t kill yourself changing a tire with a bumper jack, and I don’t know anyone who mourns their passage.
VWs used to have a screw-type jack that plugged into the jacking points built into the cars, and they worked pretty well. Some other euro-brands had similar jacks.
I’ve had cars with scissor jacks and cars with mechanical (screw driven) bottle jacks. I prefer the scissors jacks.
To be honest, I can’t remember which type jack my current cars ('97 Acura and '96 Subaru) have. If I had a flat tire on the road tomorrow, in either car, I’d have to consult the owner’s manual.
My 1969 Porsche 912 had a strange one. Like the VW that mcparadise described, its lifting arm fit into a square hole down by the rocker panel (until that rusted out after only 3 years, and I had to get a scissors jack). But rather than having a vertical screw shaft it had a straight pipe. As you pumped the handle (lug wrench) down and up, a two-piece collar would shimmy up the pipe. I guess it held itself by being cocked at a bit of an angle. To lower it you put the lug wrench in betweeen the collar pieces and gave a little downward push. That aligned the collar to the pipe, and let it slide back down – but you had to control the slide rate by the amount of push on the handle. It was easy to drop it real fast.
Sort of ingenious, and not at all obvious. One day I got a call from a colleague – a genuine mechanical engineer – who had a similar 911. He had jacked it up and couldn’t figure out how to get it back down. I went over and showed him how esy it was. It made this (former) EE feel smug.
Bumper jacks are ,luckly, history.The asian cars started the sissor jacks for compactness and weight considerations. Old VW’s with their fit in only one opening were on par with the bumpers. I always carried a telescoping hydraulic jack. Never used much,AAA was only a call away.Seems that a jack was never a real safety concern with car makers. It was to be used at your own risk!