Bridge – A load-bearing beam that runs the width of the building. This is the primary structural component that connects the runways and moves the hoist forward and backward using a trolley. A bridge can be comprised of one or two beams—more often referred to as a single girder or double girder design.
How does a bridge crane work?
Overhead cranes cover a rectangular area, moving a load side to side and backward and forward. The lifting device, called a hoist is mounted on a trolley for horizontal movement across a bridge beam connected to one or more horizontal girders which are supported at either end by end trucks.
What is the trolley on a crane?
The trolley is the mechanism that moves the hoist along the bridge girder of a crane. The hoist is moved horizontally along the top or underside of the bridge girder to position it above a load (Figure 1, Motion 2).
What is a gantry bridge?
Gantry cranes have a bridge that is supported by two a-frame rigid steel legs that rest on the floor. The legs are commonly equipped with casters so crane can be moved to different parts of a building.
What is the end of a crane called?
JIB CRANE – A crane design whereby the bridge girder (commonly called the boom) is fixed at one end, allowing the opposite end to cantilever. The fixed end generally is hinged to allow rotation. LIFT – Maximum safe vertical distance through which the hook, magnet, or bucket can move.
How much does a bridge crane cost?
COMPLETE FREE STANDING OVERHEAD BRIDGE CRANE AND HOIST
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When must crane inspections take place?
OSHA requires that all active cranes must be inspected once a year at the minimum. However, depending on the cranes usage, additional inspections will be required. Crane inspections fall under two general categories based on the intervals between inspections.
What is the difference between a crane and a hoist?
A Crane is a complex device used for moving loads in various directions. … While a hoist by itself can only raise and lower objects on a vertical plane, it is the component used for that purpose as part of a crane’s wider application. Hoists, as well as cranes, are typically used in a construction or industrial setting.
What is the hook on a crane called?
A lifting hook is a device for grabbing and lifting loads by means of a device such as a hoist or crane. A lifting hook is usually equipped with a safety latch to prevent the disengagement of the lifting wire rope sling, chain or rope to which the load is attached.
What is the difference between hoist and lift?
What is the difference between a hoist and a lift in construction? … In simple terms, a hoist is a construction device that typically uses a pulley system to raise objects upward while a construction lift typically includes an aerial platform maintained by a specific form of extension and fitted on a vehicle.
How much can a gantry crane lift?
They have spans of 140 metres (460 ft) and can lift loads of up to 840 tonnes (830 long tons; 930 short tons) to a height of 70 metres (230 ft).
What is a gantry CNC?
The gantry is the part of the CNC Router that moves along the x-axis. That’s what makes this machine a gantry style machine. The gantry allows the router to essentially float over the cutting surface. … The gantry needs to carry the z-axis, router, and the y-axis with all support pieces.
What does gantry mean?
1 : a frame for supporting barrels. 2 : a frame structure raised on side supports so as to span over or around something: such as.
What stops the crane from falling over when it lifts something?
Why Don’t Tower Cranes Fall Over? This is mostly down to the concrete base, which is massive and needs to be poured weeks before the crane arrives. The triangulated cross-member structure of the mast gives it more stability and prevents bending. Plus, it’s anchored and bolted to the ground.
How much does a crane cost?
Mobile Crane ($125,000 – $525,000+) – A common type of crane that is transportable, but may have limited range compared to the telescopic crane.
Why does the crane need to rotate?
Why does the crane need to rotate? … It has an input force or effort from the diagonal cables right at the top of the crane pulling the jib up, and a load pulling the jib down.