| Author | Message | ||
     Geoff Wootton Grand Master Username: dounraey Post Number: 939 Registered: 5-2012 |
I guess this question is prompted by JP's Nussbaum Sprinter 3000, but it applies to all hydraulic lifts. We are all aware to never trust a hydraulic jack and always use stands. Why is the same not true for a hydraulic lift. Is there a failsafe mechanism incorporated in the design? Geoff | ||
| Brian Vogel Grand Master Username: guyslp Post Number: 1636 Registered: 6-2009 |
Geoff, The Nussbaum page that JP posted states in its description: A specially designed safety device within the hydraulic circuit replaces conventional security latches and protects the lift from bagging. I would presume that this is some sort of cut-off valve that will not allow the hydraulic fluid out of the lifting mechanism itself unless intentionally opened, which is probably part of the lowering process and not automatic (JP can weigh in on this). Lift "checks and balances" as far as forcing the operator to be acutely aware of what they're about to do are fairly good. I have not used a Nussbaum or other scissor type mid-rise lift, but the companies that make these and sell them have to be acutely aware of both U.S. safety requirements and what would happen to them should one of these fail when being "used as directed." I've only used a Rotary 2-post hydraulic lift, but you can clearly hear the security latches clicking as the lift rises and passes each set. You cannot even lower the car on the lift unless you pull a lever that pulls back all the latches. If you try the lift stops coming down at the first set of latches it encounters. Brian, who would love to have a scissor lift | ||
| Geoff Wootton Grand Master Username: dounraey Post Number: 940 Registered: 5-2012 |
Hi Brian Thanks for that - I should have read the Nussbaum info more carefully. I have never considered vehicle lifts, hence my lack of knowledge about them. A quick internet search immediately picks out a Sears four post lift which has the latches you mention, spaced 4" apart. The thing that surprises me is the low price (in relative terms). I had always imagined they would be $10-20k, but not. Some of the two post lifts are as low in price as $1400. Quite a proposition, even for a keen amateur. Geoff | ||
| Robert Noel Reddington Grand Master Username: bob_uk Post Number: 469 Registered: 5-2015 |
Lifts have safety locks which drop into a slot. Also if a cable 4 post lift the tension in the cables hold a plate level. The plate has a hole through which passes a rod. If the cable goes slack the plate tipps and jams in the rod. Best lift is a 3 ton 4 post with wheel free beams. UK used price 1000 quid. I have installed a few lifts. Out side requires the lift to be water proofed. Best way is to make up hardboard templates to the bolt pattern. Dig up the site to 12" deep 4 " of rubble. Fill half way with concrete. Fit the anchor bolts using the templates to hold the bolts in line. Fit re bar and then fill the excavation with more concrete. 25ft x 10ft. The mass of concrete means it can't fall over. 250 cubic feet. Call it 26 cubic yards. About 50 tons. Some add a canopy that goes up and down with the lift. The water proofing is only necessary around the hydraulics and electrics. The cables and pulleys are well greased. | ||
| Randy Roberson Grand Master Username: wascator Post Number: 502 Registered: 5-2009 |
All the lifts I have seen use mechanical locks to keep things up in case of hydraulic failure. It does not depend on the hydraulics to hold the load, so essentially it is blocked in the up position. |
