Procedure during the selection of appropriate measures ensuring required reduction of risk in the case of machines used for wood processing is analogical for all machines, thus the principles referring to the performed activities set forth in EN-ISO 12100:2010 standard are applicable. The above-mentioned standard defines the actions directed at risk reduction taken up in a strictly determined order at the machine manufacturing stage and then at the stage of its use. At the manufacturing stage of the machine these are the following actions:
– searching for safe design solutions,
– using technical protective measures (guards, protective devices and complementary technical protective measures),
– informing the users about failure to eliminate the risk and possible protection methods during machine use.
Thus, in the case of newly designed woodworking machines, appropriate solutions should be searched for in the above-mentioned order. Additional essential requirements set forth in Directive 42/2006/EC with respect to the woodworking machines should be taken into consideration here and they refer to:
– safe fitting and guiding of the processed piece in the machine,
– ensuring stability of the machine table during operation,
– ensuring unobstructed movement of the processed piece in case of manual feeding,
– elimination of the possibility of ejection of the processed piece or its part from the machine or, if possible, limiting the risk connected with its ejection,
– machine equipped with automatic brake stopping the tool in an appropriately short time if there is a risk of contact with moving tool upon machine switch off,
– elimination or reduction of risk of accidental injuries connected with the tool built in the machine which is not fully automated.
In the case of electrically driven hand-held wood processing machines, additionally the requirements for portable, hand-held or manually operated wood processing machines should be taken into account and they refer to:
– ensuring the stability of the machine during its use by means of a supporting surface of sufficient size and sufficient number of appropriately arranged handles and supports of an appropriate size,
– placing control elements for start-up and stop of the machine in a manner enabling the operator to use them without releasing the handles, (except where technically impossible, or where there is an independent control device, but then the safety of machine use has to be ensured in other manner),
– not producing the risk of accidental start-up or continuation of machine operation after the release of handles by the operator, (if satisfying this requirement is not technically possible, equivalent measures should be applied),
– the possibility to visually observe the cutting zone of the cutting tool,
– uncomplicated start-up and stop of the machine by means of adequately designed and built machine handles,
– instructions in user manual concerning the total value of vibrations transmitted by portable hand-held or hand-guided machines, to which the hand-arm system is subjected, if this value exceeds 2.5 m/s2, or indication in the instructions that this value does not exceed 2.5 m/s2 (these values have to be either actually measured for a given machine or defined based on the measurements performed for technically equivalent machine, representative for the machine that will be manufactured. The operating conditions during measurement and the methods used for measurement or the reference of the harmonised standard applied must be specified, together with the indication of measurement uncertainty),
In the case of majority of machines for wood processing, especially fixed and transportable ones, but also in the case of portable and hand-held ones there are type C harmonised standards established, in which appropriate safety measures are proposed and ready solutions ensuring required risk reduction are presented. Thus, it is sufficient to identify a standard appropriate for a given machine and apply solutions proposed there.
Then, in the case of atypical wood processing machine, even if no type C harmonised standard has been established for it, it is possible in most of the cases to apply the same or very similar solutions taken from type C harmonised standards for other machines with similar structure or function. In such a case, however, it is necessary to properly determine which of the solutions in harmonised standards will be appropriate in a given case, so in other words, it is essential which criteria to use to determine that the given (atypical) machine has a structure or function similar to a typical machine for which a type C standard has been established, because otherwise, the solutions applied may be inadequate or even improper.
These criteria should include above all the following issues:
– machine type (fixed, transportable, portable or hand-held),
– type of cutting tool used in the machine (e.g. circular saw, band saw, milling cutter),
– number of cutting tools and their positioning in the machine (e.g. a tool operating in a horizontal plane or vertical plane, upper- or lowerspindle, on the vertical or horizontal spindle)
– type of processing (e.g. counter-rotating, concurrent, longitudinal, transverse),
– hand-fed (mechanised, manual),
– advance (mechanised, manual),
– feed movement (of the material, table or holder with the material, cutting tool unit),
– operating movement (of the cutting tool, of the processed material).
The following activity should be the search in the set of type C harmonised standards for wood processing machines for a standard (or standards) on the compliance with atypical woodworking machine in a maximum number of the above criteria. After finding such a standard (or standards), it needs to be verified whether the solution proposed in a harmonised standard or similar solution can be applied to atypical machine and if it will be correctly fulfilling its functions. If so, then the selection of a safety measure ensuring required risk reduction may be finished.
If for any reasons, appropriate solution (type C standard for a similar machine) is non-existent or it may not be applied to atypical machine, then the application of other solutions may be attempted. In such a case, the examples taken from the EN ISO 12100 standard may be used, and in the case of fixed and transportable machines – from the EN ISO 12100 standard together with EN 691 standard setting forth the details for these solutions with respect to the wood processing machines.
In both cases, i.e. upon adopting ready solution from a harmonised type C standard and in the case of use of other solution (safety measure), it needs to be verified whether they enable proper fulfilment of required functions ensuring required risk reduction.
Applied safety measures may be segregated according to the safety triad, and the risk assessment should be performed in stages, as proposed in a general part for all the machines.