Mickwhitt 5,014 #1 Posted December 21, 2024 Hi all. How the devil does a screw type car jack work? Specifically this type of jack..... I know there is a bevel gear in there which is turned by another bevel gear for the jack handle. The gear is threaded in the centre and this rotates around the lower threaded pillar thus lifting it. But how is the pillar stopped from turning with the bevel gear? I'm thinking a key way, but I'm not sure exactly how they are made. I may have to buy one and take it to bits. Mick 1 Share this post Link to post Share on other sites
ri702bill 8,963 #2 Posted December 21, 2024 Mick... search for Duff Norton. They are domestic Manufacturers of screw actuators. They did a YT video on how to dis-assemble and re-assemble a 5 ton unit. The mechanical advantage thru the gear reduction and bearings requires very little rotational force on the input. I have used these in the past on Factory Automation where an entire work station needed to be either raised or lowered per the height of the product being made... 1 Share this post Link to post Share on other sites
Wayne0 925 #3 Posted December 22, 2024 (edited) Interesting piece you've got there, Mick. This was in the trunk of the 1953 Buick I bought in 1973. I have no idea as to age, but it's jacked it's share of machinery! "Buckeye Booster No1" Buckeye Jack MFG Co Alliance, Ohio. Edited December 22, 2024 by Wayne0 1 Share this post Link to post Share on other sites
953 nut 57,861 #4 Posted December 22, 2024 2 hours ago, Mickwhitt said: how is the pillar stopped from turning with the bevel gear? You hold on to it until it makes contact with the car's frame, once it has a load it won't turn any more. 2 Share this post Link to post Share on other sites
Handy Don 13,340 #5 Posted December 22, 2024 (edited) 1 hour ago, 953 nut said: You hold on to it until it makes contact with the car's frame, once it has a load it won't turn any more. ‘xactly! Edited December 22, 2024 by Handy Don 1 Share this post Link to post Share on other sites