ASME B30.20:2003 pdf download

ASME B30.20:2003 pdf download BELOW-THE-HOOK LIFTING DEVICES
SECTION 20-0.3:DEFINITIONS FOR CHAPTER 20-1chain/hand wheel: a device for manually operating a lifter.friction-type pressure gripping lifters: lifters that grip theload without significant or harmful permanent deforma-tion of the load surface (see Fig. 1).
grip rafio: the ratio of the sum of the horizontal forceson one side of the load to the live weight of the load.For example, if the total horizontal force on one side ofthe load is 100,000 lb and the live load is 50,000 1b, thegrip ratio is 2.For purposes of this calculation, theweight of the load does not include the weight of thelifter (see Fig. 2).
gripping force: the force the lifting device exerts on theload.
irdentation-type pressure gripping lifters: lifters that carrythe load by applying force to indent the sides of theload (see Fig. 3).
ingot turnooer grab: a manipulating lifter [Fig.4, sketch(e)].
latch: a device for holding a lifter in the open or closedposition.
lafchs , automatic: a sequencing latch mechanism operatedby lifter motion.
lifting beam (spreader bea): a load supporting lifter [seeFig.5, sketch (a)].
lock bar sheef lifter: a supporting lifter [see Fig. 5,sketch (j)].
manipulafing lifter: a lifter that rotates the load about oneor more axes during the lifting process (see Fig. 4).
mechanical lifting device: a mechanism composed of twoor more rigid parts which move with respect to eachother for attaching a load to a hoisting device.
service, heavy: that service which involves operationwithin the rated load limit that exceeds normal service.seroice, normal: that distributed service which involvesoperation with various weights within the rated loadlimit, or uniform loads less than 65%of rated load.service, sezvere: that service which involves normal orheavy service with abnormal operating conditions.structural lifting deoice: a lifter consisting of an assemblyof rigid parts designed to hold and attach a load to ahoisting device.
suspporting lifter: a lifter that carries the load on rigidprojection(s) or bearing surface(s) (see Fig. 5).
SECTION 20-0.4:DEFINITIONS FOR CHAPTER 20-2breakazway force: the external force that is required toseparate the vacuum pad or vacuum lifting device fromthe load when applied perpendicular to the attachmentsurface.
four-pad powvered vacuun lifter: see Fig. 6,sketch (d).four-pad pozoered oacwum lifter manipulator: see Fig. 6,sketch (e).
high-temperature surface: a condition where the surfaceto which the vacuum pad (or pads) is attached is above250F (120°C).
horizontal lift: a condition where the surface to whichthe vacuum pad (or pads) is attached is in a horizontalplane.
low-femperature service: a condition where the surface towhich the vacuum pad (or pads) is attached is below0°F(-18C).
multiple-pad mechanical voacen lifter: see Fig.6, sketch (c).nonporous material: a material that is not permeable byfluid.
peel off: a prying action that takes place when deflectionof an overhanging load exceeds the compensating abilityof the vacuum pad or vacuum lifting device, resultingin loss of load.
porous waterial: a material that is permeable by fluid.sealing ring: that part of the vacuum pad which formsthe seal of the vacuum chamber between the vacuumpad body or vacuum lifting device and the attachedmaterial.
service, heavy: that service which involves operationwithin the rated load limit that exceeds normal service.seroice, normal: that distributed service which involvesoperation with various weights within the rated loadlimit, or uniform loads less than 65%of rated load.