BS ISO 13772:2018,Forestry machinery — Portable chain-saws — Non-manually actuated chain brake performance.BS ISO 13772:2018 pdf free download here.
ISO 13772:2018 specifies a method for checking the functioning and performance of the non-manually actuated chain brake on an electric or gasoline engine powered, portable hand-held chain-saw.
2 Normative references
ISO 6531, Machinery for – Portable chain-saws – Vocabulary.
4 Performance requirements
The non-manually actuated chain brake function shall be checked on a new normal production saw equipped with the shortest and longest guide bars specified in the instruction handbook, but no longer than 500 mm. Battery-powered chain-saws shall be checked with the lightest and heaviest battery packs.
When tested in accordance with Clause 8, the performance of the actuation function of a non-manually actuated chain brake is considered acceptable if each of the horizontal and vertical acceleration levels at which the chain brake actuates is below the appropriate threshold level as shown in Figure 1 a), b) or c) for different chain-saw types and sizes.
5 Principle
The chain-saw shall be mounted on a test rig as shown in Figure 3. The drop mass falls from a defined height on the rocker and accelerates the chain-saw on the opposite side, The drop height shall be increased until the actuation of the non-manually actuated chain-brake occurs.