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Crane Handbook Glossary K-O

Click below to follow the links to individual sections of the Crane Handbook Glossary.

A - E    F - J    K - O    P - S    T - Z

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KSI

Bridge Crane

Kips per square inch, measurement of stress intensity. (CMAA Spec. 70)

Kip

Bridge Crane & Hoist

A unit of force, equivalent to 1000 pounds. (CMAA Spec. 70)

Knee brace

General

The diagonal structural member joining the building column and roof truss. (CMAA Spec. 70)

Latch

Below hook device

A device for holding a lifter in the open or closed position.  (ASME B30.20-1985)

Latch, automatic

Below hook device

A sequencing latch mechanism op­erated by lifter motion. (ASME B30.20-1985)

Latch, hook

Hoist

A device used to bridge the throat opening of a hook. (WCH)

Lateral forces

Runway

Horizontal forces perpendicular to the axis of the member being considered. (CMAA Spec. 70)

Lateral hook travel

Hoist

The lateral movement of the load hook between its position at the upper limit of travel and its position at the lower limit of travel.  (ASME HST-4M-1991)

Lefthand end

Bridge Crane

A reference to parts or dimensions on the viewer’s left of the centerline of span, established when facing the drive girder side of the crane. (WCH)

Lift

Hoist

The maximum vertical distance through which the load hook can travel, and the total allowable hook movement between its upper limit of travel and its position when at the lower limit of travel (see Fig. 1)

Lift (hook travel)

Hoist

The maximum vertical distance through which the hook(s) can move, as determined by the length of rope and/or the number of grooves on the drum. (WCH)

Lift cycle

Bridge Crane & Hoist

Single lifting and lowering motion (with or without load). (CMAA Spec. 70)

Lift limiting device

Hoist

An electrical, mechanical, or electromechanical device for limiting the upward or downward travel of the load hook at the extremities of lift. This device may limit lift at any point within the extremities of lift, if designed to be adjustable.  (ASME HST-4M-1991)

Lift section

Monorail

A mechanism which will lift a section of track out of alignment with a stationary track. (ANSI MH 27.1-1981)

Lifting beam (spreader beam)

Below hook device

A load supporting lifter (see Fig. 2).  (ASME B30.20-1985)

Lifting devices

Hoist

Devices which are not normally reeved onto the hoist rope or chain, such as hook-on buckets, magnets. grabs. and other supplemental devices used for ease of handling certain  types of loads. The weight of these devices is to be considered part of the load to be lifted.  (ASME B30-16-1993)

Limit device

Bridge Crane Control

A device which is operated by some part or motion of a power driven hoist to limit motion.  (ASME B30-16-1993)

Limit switch

General

A device designed to cut off the power automatically at or near the limit of travel for the crane motion. (CMAA Spec. 70)

Line contactor

Bridge Crane Control

A contactor to disconnect power from the supply lines. (CMAA Spec. 70)

Live load

General

A load which moves relative to the structure under consideration. (CMAA Spec. 70)

Load

Bridge Crane & Hoist

The total superimposed weight on the load block or hook.  (ASME B30.2-1990)

Load (capacity), rated

General

The maximum load that the lifting magnet is designated to handle by the manufac­turer.  (ASME B30.20-1985)

Load (capacity), specified application

General

A load applied to the lifting magnet when it is used to handle a specified load. (ASME B30.20-1985)

Load (maximum), specified

General

A load identified by part number or other Bridge Crane Controlled definition.  (ASME B30.20-1985)

Load bar

Hoist

A load-carrying member between carriers load block the assembly of hook or shackle, swivel, bearing, sheaves, pins, and frame suspended by the hoist rope or load chain. This  shall include any appur­tenances reeved in the hoisting rope or load chain.  (ASME B30.11-1993)

Load block

Hoist

The assembly of hook or shackle, swivel, bearing, sheaves, pins, and frame suspended by the hoisting rope or load chain. This shall include any appurtenances reeved in the  hoisting ropes.  (ASME B30.2-1990)

Load carrying flange.

Bridge Crane & Monorail

The lower flange of the track on which the load bearing wheels roll. (ANSI MH 27.1-1981)

Load cycle

Bridge Crane & Hoist

One lift cycle with load plus one lift cycle without load. (CMAA Spec. 70)

Load hook

Hoist

the hook used to connect the load to the hoist.  (ASME HST-4M-1991)

Load suspension parts—

Hoist

The load suspension parts of the hoist are the means of suspension (hook or lug). the structure or housing which supports the drum or load sprocket. the drum or load sprocket. the rope or load chain, the sheaves or sprockets. And the load block or hook.  (ASME B30-16-1993)

Load, dead

Bridge Crane & Hoist

The load(s) on a portion of the crane, which remain(s) in affixed position relative to the member being considered. (WCH)

Load, live

Bridge Crane & Hoist

A load which moves or varies relative to the member being considered. For the trolley, the live load consists of the rated load plus the weight of the block. For the bridge,  the live load consists of the rated load plus the weight of the trolley. (WCH)

Load, rated

Hoist

The maximum load designated by the man­ufacturer for which a crane or individual hoist is designed and built.  (ASME B30-17)

Lock bar sheer lifter

 

A supporting lifter (see Fig. II) .  (ASME B30.20-1985)

Longitudinal stiffeners

Bridge Crane

Horizontal members attached to the web of the bridge girder to prevent web buckling. (CMAA Spec. 70)

Low temperature service

Below hook device

A condition where the sur­face to which the vacuum pad (or pads) is attached is below 00F (—180C). (ASME B30.20-1985)

Lug

Bridge Crane & Monorail

A mechanical device fixed to the end truck or wheel yoke which will prevent the crane or carrier from falling in the event of a wheel or axle failure. (ANSI MH 27.1-1981)

Lug suspended

Hoist

A hoist suspended from a trolley or permanent structure by means of bolt(s) or pin(s) through a rigid or swivel type lug.  (ASME HST-4M-1991)

Magnet

Below hook device

An electromagnetic device carried on a hoist hook, used to pick up and carry loads magnetically. (ANSI MH 27.1-1981)

Magnet, lifting

Below hook device

(a)          electromagnet, battery-powered — a magnet which requires continuous current supplied by a battery to maintain holding force (see Fig. 32)

(b)          electromagnet, externally powered — a magnet suspended from a crane which requires power from a source  external to the crane

(c)          permanent magnet, electrically Bridge Crane Controlled — a magnet which derives holding force from permanent magnet material and requires current only during the pe­riod of attachment or release (see Fig. 33)

(d)          permanent magnet. manually  Bridge Crane Controlled — a magnet which derives holding force from permanent magnet material and requires a manual effort during pe­riod of attachment or release (see Fig. 34).  (ASME B30.20-1985)

Magnet, lifting, close proximity operated

Below hook device

A lifting magnet used in such a fashion that the operator man­ually positions the magnet on the load, and manually guides the magnet and load during a lift.  (ASME B30.20-1985)

Magnet, lifting, close proximity operated

Below hook device

A lifting magnet used in such a fashion that the operator man­ually positions the magnet on the load, and manually positions the magnet and load during a lift.  (ASME B30.20-1985)

Magnet, lifting, general application

Below hook device

Lifting magnets that are intended by the manufacturer to be used on a number of different geometrical shapes and do not fall under the category of remotely operated lifting magnets.  (ASME B30.20-1985)

Magnet, lifting, remotely operated

Below hook device

A lifting magnet which does not require the operator or other personnel to be in close proximity to the magnet or its load while the magnet is in use (see Figs. 35 and 36).  (ASME B30.20-1985)

Magnet, lifting, submersible

Below hook device

— a special magnet that has been designed to be immersed in liquid.  (ASME B30.20-1985)

Magnet. Lifting, specified application

 

Lifting magnets that are designed for lifting specified geometrical con­figurations and weights of designated parts, identified by part number or other Bridge Crane Controlled definition and used in a Bridge Crane Controlled manner.  (ASME B30.20-1985)

Magnetic Bridge Crane Control

Bridge Crane Control

A means of Bridge Crane Controlling direction and speed by using magnetic contactors and relays. (CMAA Spec. 70)

Main hoist

Hoist

The primary hoist mechanism provided for lifting and lowering the rated load.  (ASME B30.2-1990)

Main line contactor

Bridge Crane Control

A magnetic contactor used in the incoming power circuit from the main line collectors. (CMAA Spec. 70)

Main line disconnect switch

Bridge Crane Control

A manual switch which breaks the power lines leading from the main line collectors. (CMAA Spec. 70)

Man trolley

Monorail

A trolley having an operator’s cab at­tached to it.  (ASME B30.2-1990)

Manipulating lifter

Below hook device

A lifter that rotates the load about one or more axes during the lifting process (see Figs. 22 through 26).  (ASME B30.20-1985)

Manual-magnetic disconnect switch

Bridge Crane Control

A power disconnecting means consisting of a magnetic-contactor that can be operated by remote pushbutton and can be manu­ally operated by a handle on the switch. (CMAA Spec.  70)

Master switch

Bridge Crane Control

A manually operated device which serves to govern the operation of contactors and auxiliary devices of an electric Bridge Crane Control. (CMAA Spec. 70)

Match marking

General

Identification of non-interchangeable parts for reassembly after shipment. (CMAA Spec. 70)

Mean effective load

Bridge Crane & Hoist

A load used in durability calcula­tions accounting for both maximum and minimum loads. (CMAA Spec. 70)

Mechanical braking means

Bridge Crane & Hoist

A method of Bridge Crane Control­ling or reducing speed by friction.  (ASME HST-4M-1991)

Mechanical load brake

Hoist

An automatic type of fric­tion brake used for Bridge Crane Controlling loads in a lowering direction. This unidirectional device requires torque from the motor to lower a load but does not impose additional load on the motor when lifting a load..  (ASME HST-4M-1991)

Mechanically interlocked

Bridge Crane Control

A mechanical device which prevents operation of opposite Bridge Crane Controls at the same time. (ANSI MH 27.1-1981)

Messenger track

Bridge Crane

A horizontal member, mounted along a handrail or girder, supporting movable carriers from which festooned wires are hung. The festooned wires may be used to transmit current  from the bridge to the trolley or from the bridge to a pendant Bridge Crane Control unit. (WCH)

Mill duty crane

Bridge Crane & Hoist

Service classification covered by AISE Standard No. 6, ‘Specification for Electric Overhead Travel­ing Cranes for Steel Mill Service’. (CMAA Spec. 70)

Monorail

Monorail

An overhead track upon which carriers travel, used to transport loads. (ANSI MH 27.1-1981)

Motor circuit switch

Bridge Crane Control