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Crane Handbook Glossary P-S

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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Parts (lines)

Hoist

Number of lines of rope supporting the load block or hook.  (ASME HST-4M-1991)

Patented track

Bridge Crane

A generic term referring to crane and monorail equipment built in accordance with the MMA specification utilizing a composite track section incor­porating a proprietary bottom flange shape. (CMAA Spec 74)

Pawl

Hoist

A device for holding the machinery against un­desired rotation by engaging a ratchet.  (ASME B30-16-1993)

Peel-off

Below hook device

A prying action which takes place when de­flection of an overhanging load exceeds the compensat­ing ability of the vacuum pad or vacuum lifting device resulting in loss of load.  (ASME B30.20-1985)

Pendant pushbutton station

Bridge Crane & Hoist

Means suspended from the crane operating the Bridge Crane Controllers from the floor or other level beneath the crane. (CMAA Spec. 70)

Pitch diameter

Hoist

The distance from center to center of a rope passing over a sheave or wound on a drum, measured across the diameter of the sheave or drum power transmission parts the power transmission parts of the hoist are the machinery components, in­cluding the gears, shafts, clutches, couplings, bear­ings, motors, and brakes.  (ASME HST-4M-1991)

Pitch diameter (rope)

Hoist

Distance through the center of ~ drum or sheave from center to center of a rope passed about the periphery. (CMAA Spec. 70)

Plain reversing Bridge Crane Control

Bridge Crane & Hoist

A reversing Bridge Crane Control which has identical characteristics for both directions of motor rotation. (CMAA Spec. 70)

Plugging

Bridge Crane Control

A Bridge Crane Control function which accomplishes braking by reversing the motor line voltage polarity or phase sequence. (CMAA Spec. 70)

Plugging relay

Bridge Crane Control

A current relay used on a bridge or trolley Bridge Crane Control panel which senses current in the motor secondary circuit of an alternating current motor and limits reverse torque of the motor to the first Bridge Crane Control point until the motor rotation has stopped. In a direct current Bridge Crane Control panel, the relay performs the same function by establishing a patented sensing circuit at the motor  armature. (Sometimes called an anti- plugging relay.) (WCH)

Primary upper limit device

Hoist

The first device that, when actuated, limits hoisting motion in the upward direction.  (ASME B30.2-1990)

Important, this is not to be used as a operational limit switch.

Process crane

Bridge Crane

 

Protective panel

Bridge Crane Control

An assembly containing overload and undervoltage protection for all crane motions. (CMAA Spec. 70)

Pulpit Bridge Crane Controlled

Bridge Crane & Monorail

A unit operated from a fixed operator station not attached to the crane. Pushbutton Station. A device consisting of pushbutton operated contacts in an enclosure used by the  operator for Bridge Crane Control of the powered motions of the crane, hoist, and other auxiliary equipment. (ANSI MH 27.1-1981)

Push button station

Hoist

An electrical Bridge Crane Control device, con­sisting of push button operated contacts, used by the oper­ator for the Bridge Crane Control of the powered motions of the crane, hoist, and other  auxiliary equipment.  (ASME B30-17)

Qualified person

Regulatory

A person who, by possession of a recognized degree or certificate of professional standing or by extensive knowledge, training, and experience, has successfully demonstrated the ability to solve or resolve problems relating to the subject matter and work. (ASME B30-17)

Radio Bridge Crane Controlled

Bridge Crane Control

A unit operated from a radio transmitter located at a point not mechanically attached to the device being Bridge Crane Controlled. (ANSI MH 27.1-1981)

Rail sweep

Bridge Crane

A device attached to the crane and located in front of the crane’s leading wheels to push aside loose obstructions.  (ASME B30-17)

Rail, bridge

Bridge Crane

The track supported by the bridge girder(s), on which the trolley travels. (WCH)

Rail, runway

Runway

The track supported by the runway beams, on which the crane travels. (WCH)

Rated load (capacity)

Bridge Crane & Hoist

The maximum load designated by the manufacturer for which a crane or individual hoist is designed and built.  (ASME B30.2-1990)

Reach

Hoist

Reach is equal to lift plus headroom. (ASME HST-4M-1991)

Reeving

Hoist

The reeving of the hoist is the path of the rope between the hoist and the load block

—     (a)  double reeving two parts of line leading off of the drum (see Fig. 2).

—     (b)  single reeving one part of the line leading off of the drum (see Fig. 2).   (ASME HST-4M-1991)

Regenerative braking means

Hoist

A method of Bridge Crane Control­ling speed in which the electrical energy generated by the motor is fed back into the power system rope refers to wire rope unless otherwise speci­fied.   (ASME HST-4M-1991)

Regulated speed

Bridge Crane & Hoist

A function which tends to maintain constant motor speed for any load for a given speed setting of the Bridge Crane Controller. (CMAA Spec. 70)

Remote Bridge Crane Controlled

Bridge Crane Control

A unit operated from a Bridge Crane Control station located at a point not mechanically attached to the device being Bridge Crane Controlled. (ANSI MH 27.1-1981)

Righthand end

Bridge Crane

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

Rope

Hoist

Refers to wire rope unless otherwise specified.  (ASME B30-17)

Rope drum

Hoist

The cylindrical member around which the rope is wound for lifting and lowering the load.  (ASME HST-4M-1991)

Rope sheave

Hoist

A grooved wheel used with a rope to change direction and point of application of a pulling force. (ASME HST-4M-1991)

Rotary switch

Monorail

A track switch with a movable in­ner frame containing straight and/or curve sections of track. The inner frame can be rotated around a vertical axis to align these tracks with other tracks for routing carriers from one track to another. (ANSI MH 27.1-1981)

Rotating axle

Bridge Crane

An axle which rotates with the wheel.(CMAA Spec. 70)

Running sheave

Hoist

A sheave that rotates as the hook is lifted or lowered.  (ASME HST-4M-1991)

Runway

Runway

The rails, beams, brackets and framework on which the crane operates. (CMAA Spec. 70)

Runway conductors

Runway

The main conductors mounted on or parallel to the runway which supplies current to the crane. (CMAA Spec. 70)

Runway rail

Runway

The rail supported by the runway beams on which the bridge travels. (CMAA Spec. 70)

S section

Bridge Crane & Runway

A standard beam shape as defined by the American Institute of Steel Construction. (CMAA Spec. 74)

Safety lug

Bridge Crane

A mechanical device fixed securely to the end truck or trolley yoke which will limit the fall of the crane or carrier in case of wheel or axle failure. (CMAA Spec. 74)

Service platform

Bridge Crane

A means provided for workers to per­form maintenance, inspections, adjustments, and repairs of cranes  (ASME B30-17)

Service, heavy

Bridge Crane & Hoist

That service which involves operation within the rated load limit which exceeds normal service.  (ASME B30-16-1993)

Service, normal

Bridge Crane & Hoist

That distributed service which in­volves operation with randomly distributed loads within the rated load limit, or uniform loads less than 65% of rated load for not more than  15% of the time for man­ually operated hoists, and 25% of the time for electric-or air-powered hoists.  (ASME B30-16-1993)

Service, severe

Bridge Crane & Hoist

That service which involves normal or heavy service with abnormal operating conditions.  (ASME B30-16-1993)

Shall

Regulatory

This word indicates that a rule is mandatory and must be followed.  (ASME B30.2-1990)

Shear breakaway force

Below hook device

The external force that is re­quired to separate or slide the vacuum pad or vacuum lifting device on the load when the force is applied par­allel to the attached load surface. (ASME B30.20-1985)

Sheave

Hoist

A grooved wheel or pulley used with a rope or chain to change direction and point of application of a pulling force. (CMAA Spec. 70)

Sheave, running

Hoist

A sheave which rotates as the load block is lifted or lowered.  (ASME B30-16-1993)

Sheave; nonrunning (equalizer)

Hoist

A sheave used to equalize tension in opposite parts of the rope. Be­cause of its slight movement, it is not termed a run­ning sheave. .  (ASME B30.2-1990)

Should

Regulatory

This word indicates that a rule is a recom­mendation, the advisability of which depends on the facts in each situation.  (ASME B30.2-1990)

Side pull

Hoist

The component of the hoist pull acting hori­zontally when the hoist lines are not operated vertically.  (ASME B30-17)

Simple beam

General

A structural member supported and unrestrained at each end and subjected to loads acting transversely to its longitudinal axis. (ANSI MH 27.1-1981)

Single reeved

Hoist

 

Skeleton cab

Bridge Crane

Same as dummy cab. (CMAA Spec. 70)

Skewing forces

Bridge Crane

Lateral forces on the bridge truck wheels caused by the bridge girders not running perpen­dicular to the runways. Some normal skewing occurs in all bridges. (CMAA Spec. 70)

Span

Bridge Crane

The horizontal distance center-to-center of runway rails. (CMAA Spec. 70)

Splice 

Bridge Crane & Monorail

A mechanical device used to join the adjacent ends of track sections.  (ASME B30.11-1993)

Spring return

Bridge Crane Control

A device used on a manual Bridge Crane Controller, master switch, or pushbutton to cause the unit to return automatically to the neutral position, when released by the operator. (WCH)

Sprocket, idle

Hoist

A freely rotating device that changes the direction of the load chain.  (ASME B30-16-1993)

Sprocket. Load

Hoist

A hoist component that transmits mo­tion to the load chain. This component is sometimes called load wheel, load sheave, pocket wheel, or chain wheel.  (ASME B30-16-1993)

Spur track

Monorail

A fixed track arranged to interlock with an adjacent crane girder to permit passage of carriers from the spur track to the crane, and vice versa.  (ASME B30.11-1993)

Squaring shaft

Bridge Crane

A driven shaft which transmits torque to drive wheels operating on two or more tracks. (ANSI MH 27.1-1981)

Standby equipment

Bridge Crane & Hoist

Equipment that is not in regular service but which is used occasionally or intermittently as required.  (ASME B30.11-1993)

Static Bridge Crane Control

Bridge Crane Control

A method of switching electrical circuits without the use of contacts. (CMAA Spec. 70)

Stationary track.

 

A fixed track attached to the building or supporting structure. (ANSI MH 27.1-1981)