Boom rams The telescoping sections of mini crane booms are extended or retracted using hydraulic rams and, with some machines, chain drives, located inside the boom. There are single ram systems, where one ram is used; and multi-ram systems, where two or more rams are used, of which one design is a double-acting ram, where one ram can be extended inside another ram.
Recoil drum The recoil drum is another key part of the mini crane’s load monitoring system (LMI). The boom length is measures by a wire which extends from a drum as the boom is extended, which gives the device its name. Data from the recoil drum is stored by the 3B6 LMI system and displayed on the driver tiller control panel. This data is important because the further the load is from the crane, the less weight the crane can lift.
Driver tiller Mini cranes can be driven and operated in a number of ways. Some larger cranes have a built-in seat for driver / operators to sit on. This particular mini crane has a drive tiller. This has a number of levers and buttons used by the mini crane operator to move the machine and control the lift function.
Jib head The jib head is a device attached to the end of the boom, from which the rigging cable, chain or strap is hung. On the Valla 22E mini crane (shown), the orientation of the jib head can be adjusted, depending on the nature of load and objective of the lift.
Articulated rear axle Pick and carry mini cranes have a fixed boom. So, to slew a mini crane, the entire machine must move. Because the crane has an articulating rear axle, it can slew with ease in either direction. Mini cranes turn on their front axles. The weight of the crane acts as the counter balance.
Non-marking tyres Mini cranes can be fitted with non-marking tyres, as this one is. These are ideal for working inside buildings and clean environments. The tyres are solid, but are designed to flex under load, increasing the surface area in contact with the ground.
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hird.co.uk/anatomy
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