Compact system for lifting and moving a pressurized tank
A hoist with a cradle for coupling with a pressurized tank. A linear actuator assembly raises the cradle above the floor surface. A base with casters allows a raised tank to be safely lifted and transported by a single operator. The cradle can be rotated and locked in a vertical or horizontal position for cylinder insertion and removal in EMS vehicles with either a vertical or a horizontal stowage compartment. When handling a horizontal cylinder stowage situation, an embodiment of the cradle features a retractable foot to allow the cylinder to be slid from the cradle into the compartment bottom first. Another embodiment has a fixed foot and allows the cylinder to be slid from the cradle into the compartment top first. Safety interlocks are provided to prevent rotation of the cradle if the foot is in the wrong position with respect to the horizontal orientation of the cradle.
1. A device for lifting and transporting a pressurized cylinder, the device comprising:
a base;
a cradle having a foot to support the cylinder when disposed within the cradle, the foot movable between an extended position and a retracted position;
a linear actuator mounted to the base and supporting the cradle for vertical positioning of the cradle relative to the base;
a pivot mechanism rotatably joining the cradle to the actuator, the pivot mechanism positioning the cradle between a vertical position and a horizontal position; and
a linkage interfaced to the pivot mechanism, the linkage automatically locking the foot in the extended position when the pivot mechanism positions cradle is in the vertical position, the linkage automatically unlocking the foot when the pivot mechanism positions the cradle is in the horizontal position to enable the foot to be rotatably positioned from the extended position to the retracted position;
wherein the foot is attached to the lowest portion of the cradle and supports the weight of the cylinder while in the extended position, and when in the retracted position, enables the cylinder to slide from the cradle, bottom first, when the cradle is horizontal.
2. The device of claim 1 wherein the cradle further comprises a friction reducing surface chosen from the group consisting of polymer, natural fiber, and metal.
3. The device of claim 1 wherein the pivot mechanism allows the cradle to rotate approximately 90 degrees between the vertical and horizontal positions.
4. The device of claim 1 wherein the pivot mechanism comprises: a first bracket; a second bracket; and a supporting shaft, wherein the supporting shaft attaches the first bracket to the second bracket, and wherein the first bracket rotates with respect to the second bracket.
5. The device of claim 4 wherein the pivot mechanism further comprises: a locking pin, wherein the locking pin engages the first and second bracket to prevent rotation.
6. The device of claim 5 wherein the locking pin is spring-loaded such that manual force is required to disengage the first and second bracket.
7. The device of claim 1 wherein the foot is operable only when the cradle is approximately horizontal.
8. The device of claim 1 wherein the cradle can rotate only when the foot is extended.
9. A method, the method for using the device of claim 1 to insert a cylinder into a horizontal stowage compartment on an EMS vehicle in a bottom first fashion, the stowage compartment having mounts upon which the cylinder is to sit, the method comprising the following steps: (a) fastening the cylinder to the vertical cradle with the foot extended; (b) raising the cradle high enough such that the foot of the cradle is above the base; (c) rotating and locking the cradle approximately 90 degrees to the horizontal; (d) positioning the device parallel to the compartment such that the bottom of the cylinder is aligned with the rails and the device is as close to the vehicle as possible; (e) retracting the foot; (f) unfastening the cylinder from the cradle; and (e) sliding the cylinder from the cradle and into the compartment such that the cylinder's valve is the last portion to enter the compartment.
10. The device of claim 1 , wherein the cradle is arcuate in shape approximating a radius of the cylinder.
11. The device of claim 1 , further comprising a rotatable handle to extend and retract the foot.