Bottle Jacks are small, portable, hydraulic piston type jacks that are named because they resemble the shape of a bottle. Bottle Jacks have been widely used for over 100 years, developed in conjunction with the growth of the automobile industry. Although they are mostly used for automotive maintenance, Bottle Jacks have many other uses. They are often used in the construction industry for holding floor joists, deck framing or for lifting foundations. They can also be found in the medical and plumbing fields and in industrial applications such as lifts and mechanical presses.
Bottle Jacks are available in a wide variety of sizes and lifting capacities. They can range in capacities from a few hundred pounds to over 100 tons. The most popular sizes are in the 2 to 20-ton range. They can equally be used in both a vertical or horizontal position.
Jack extensions are available that are made to slip over the ram of the Bottle Jack. These extensions extend the reach of the ram so that the Bottle Jack can be used to lift objects that require more clearance, such as jacking of an aircraft. The extensions can be stacked together to a height where the base of the jack can be placed on level ground, making the jack less likely to tip and its use much safer.
How Do Bottle Jacks Work?
Bottle Jacks work by the exertion of a force that acts on the bottom of the piston within the jack cylinder.
When the handle is pulled up, the hydraulic fluid is pulled from the reservoir. When the handle is pushed down, that fluid is transferred to the bottom of the piston, which lifts the piston up. The more the handle is pumped, the higher the pressure and the higher the piston moves.
Most hydraulic fluids are non-compressible so that when a load is placed on the top of the piston, the piston height will remain stationary due to the pressure underneath. When the release valve is opened, the fluid returns back into the reservoir and the piston height retracts.
Bottle Jack Safety
The operating manual of the Bottle Jack should always be consulted before use. The manual will contain important safety information that will need to be understood before operating the jack.
The Bottle Jack should always be placed on solid, level ground for stability. Bottle Jacks should never be stacked on wood or concrete blocks for extra reach. The jack extensions should always be used for situations where additional reach is required.
The Bottle Jack ram and the surface where the jack contacts the load should be cleaned before use so that a good contact is maintained during operation.
There should be adequate workspace around the jacking area so that no part of the operator is underneath the load while it is being lifted or lowered.
Bottle Jacks are only designed to lift a load. They are not made to continually hold or support the load over long periods of time. Once the load is lifted, it should be supported by adequately rated jack stands for prolonged safety.
The capacity of the Bottle Jack should be chosen so that it exceeds the lifting capacity that is required. Jacks used right at or near the capacity limit could become unstable or fail during use.
Bottle Jack Maintenance
The overall condition of the jack should be inspected regularly. The jack should be inspected for any type of damage, loose or missing components or evidence of leaking hydraulic fluid. The jack should not be used if any condition is discovered that would affect the proper operation of the jack.
The jack should be tested for proper operation. A smooth movement of the piston is critical. Any contamination from dirt, rust, or corrosion can cause uneven movement which can result in a jerky motion which can shift the load while being used.
The fluid level should be checked to ensure that it is at the proper level. The fluid level should be checked with the piston fully lowered so that all of the fluid is in the reservoir. The hydraulic fluid should be changed at a minimum of every 3 years, depending on its use.
The Bottle Jack should be stored in a clean, dry location when not in use. The ram and piston should be in the fully down position to ensure that the precision surfaces of the piston are not exposed to the environment to reduce the possibility of corrosion.