1、INTERNATIONAL STANDARD IS0 10245-5 First edition 1995-l 2-l 5 Cranes - Limiting and indicating devices - Part 5: Overhead trave llling and portal bridge era nes Appareils de levage B charge suspendue - Dispositifs limiteurs et indicateurs - Partie 5: Ponts roulants et ponts portiques Reference numbe
2、r IS0 10245-5:1995(E) ISO 102 - the crane is likely to handle unpredictable loads, which can result in overloading of the mechan- isms and structures. 4.2 The rated capacity limiter shall allow the rated load and lifting devices to be accelerated upwards with the design mean acceleration a. Normally
3、 the limiter can be adjusted and blocked to the appropriate value during tests with the rated load. For serially manufactured hoisting winches, it may be adequate to set the rated capacity limiter during workshop tests, taking into account provisions for elasticity of the bridges on which the winche
4、s are being used. 4.3 It may be necessary to fit a system to the limiter to prevent it from sensing dynamic loads during oper- ation. 4.4 The rated capacity limit setting QL shall meet the following ratios: l+E QL -q)2 g QGL where a is the design mean acceleration for hoisting; g is the acceleration
5、 due to gravity; QL is the rated capacity limit setting for the hoist medium (rope, chain, etc.); 1 IS0 10245-5:1995(E) QsL is the gross load, comprising hoist medium, fixed load-lifting attachment and the rated load (rated load = non-fixed load-lifting attach- ment + payload); (p2 is the amplifying
6、 factor used in the proof of competence calculation of the crane in ac- cordance with IS0 8686-l :I 989, subclause 6.1.2.2.1. 4.5 In special cases in which the rated capacity of the bridge or gantry crane in certain reaches and load positions is limited to values lower than the rated load of the hoi
7、sting mechanism, the rated capacity limiting system shall stop any movement that is bringing the system out of design limits. 4.6 In a crane where two or more hoisting mech- anisms are in operation in tandem, rated capacity lim- iters, working in conjunction with related motion limiters, when activa
8、ted by an overload, shall override the controls of all motions causing the overload con- dition. 5 Rated capacity indicator 5.1 Cranes shall be fitted with a rated capacity indi- cator when the rated capacity of the crane depends on the position of the load. A rated capacity indicator should also be
9、 provided when it is considered to have essential effect on im- proving crane control and safety. The rated capacity indicator shall indicate to the crane driver and, when appropriate, to those in the vicinity of the crane, when the rated capacity has been reached and/or the rated capacity limiter h
10、as overridden the controls. 5.2 In cranes for which the rated capacity depends on the location of the crab (see figure 1) and in cases described in 4.6, the rated capacity indicator shall give a continuous visual and/or acoustic warning to the crane driver whenever the load approaches the rated capa
11、city. The setting of the signal actuator depends on the type of use of the crane. In general, the warn- ing signal should be given when 90 % to 95 % of the rated capacity is reached. 5.3 Acoustic warnings shall be sufficiently loud to be heard by those to be warned above the general back- ground noi
12、se of the site of operation. The warning sound should be clearly identifiable and not liable to confusion with other common sounds. 2 0 IS0 a 1 I-“” L-d a) A minimum distance 1 between two crabs is required in order to use the full rated capacity of the crabs. With a shorter distance the rated capac
13、ity is reduced (mainly in or- der to reduce bridge weight and keep wheel loads within allowable limits). b) The rated capacity is limited on a cantilever of the crane (e.g. due to stability, corner load or strength of the beam). Figure 1 - Examples of cases where the rated capacity of a bridge or ga
14、ntry crane is limited 6 Motion- and performance-limiting devices 6.1 Motion limiters 6.1.1 Any crane motion which has a restriction of movement in the design of the crane shall be provided with a motion limiter. Guidance for the application of the most common types of motion limiters for usual crane
15、 motions is given in table 1. 0 IS0 IS0 102455:1995(E) Table 1 - Selection of motion limiters Type of motion limiter Motion End stop Buffer Cut-out limit Slow-down Back-up zlimit switch device switch Hoisting, in general A x 1) Hoisting, high risk applications A A Lowering A Travelling vLt 0,63 m/s
16、A 0 0 0 vLt a 0,63 m/s A I I I Traversing vet 0,80 m/s A 0 0 0 vet a 0,80 m/s A I I I Trolley slewing 2) A 0 0 Hook slewing 2) A 0 1) 0 1) Boom hoisting A X A X NOTE -A = required; x = recommended; 0 = at least one type of motion limiter recommended; I = at least one type of motion limiter required
17、3). 1) A torque limiter may replace the motion limiter indicated in this table. 2) Apply only when the slewing angle is restricted. 3) For higher velocities and/or masses (kinetic energies), more than one type of motion limiter may be required. 6.1.2 Accelerations applied to the structures due to th
18、e action of limiters shall be taken into account in design. 6.2 Performance limiters Performance limiters should be provided based upon application requirements which include crane control and safety. 6.1.3 The motion limiters shall be designed so that the maximum acceleration to which the crane dri
19、ver is subject is less than 4 m/s*. 7 Motion- and performance-indicating devices 6.1.4 When there is a possibility of collision of two cranes, this shall be taken into account in the design of the motion limiters. Motion- and performance-indicating devices, in accord- ante with IS0 10245-1, should b
20、e provided based upon application requirements which include crane control and safety. IS0 10245-5:1995(E) ICS 53.020.20 Descriptors: handling equipment, lifting equipment, cranes (hoists), travelling cranes, portal bridge cranes, safety devices, limiting devices, signal devices, specifications, safety requirements. Price based on 3 pages
