Power-chuck DURO-NC - RÖHM - #9

(i.e. it should be limited accordingly). Even a singular incident where the permitted values are exceeded can lead to damage or injury and represent a hidden source of risk, even if not immediately detected. The manufacturer should be informed immediately in such cases so that an inspection offunctional and operational safety can be conducted. Further safe operation of the clamping unit can only be guaranteed in this manner.

Residualriskscanemanatefrominsufficientrotarycompensa-tion, see § 6.2 No. e) EN 1550. This applies in particular where high speeds are involved, when machining asymmetrical workpiecesorwhen usingdifferenttopjaws. Thechuckshould bedynamicallybalancedwiththeworkpiecemountedinaccor dance with DIN ISO 1940 to prevent any resulting damage.

The required clamping forces and / or permissible maximum speed for the chuck should be determined for a specific task in accordance with VDI Guideline 3106 (governing the determination ofpermissiblespeeds forrotarychucks(jawed chucks)). High centrifugal forces associated with special clam­ping inserts which, due to their design, are heavier or larger than the clamping inserts allocated to the clamping medium should be taken into consideration when determining the required clamping force and permissible speed.

VDI Guideline 3106 governing the determination of permissi-blespeedsforrotarychucks(jawedchucks)shouldalwaysbe consulted when using clamping inserts / workpieces.

1.Use of other / additional clamping inserts Theoperatormustruleoutuseofthechuckataninordinately excessive speed and, consequently, the generation of excessive centrifugal force if clamping inserts other than those intended for this clamping fixture are used. A risk exists otherwise that the workpiece will not be adequately clamped. The chuck manufacturer and /or designer should therefore be consulted in all such cases.

Soastoprotecttheoperatoragainstejectedpartsandinline with DIN EN 12415aseparating protectiveequipmentmust be fitted to the machine tool, the resistance capability of which is specified in so-called resistance classes. Should new clamping sets be used on the machine, their approved suitabilitymustfirstbechecked.Thisalsoincludesclamping setsand/orpartsthereofmanufacturedbytheuserhimself. This approved suitability is influenced by the resistance class of the protective equipment, the mass of the possible ejected parts (determined by calculation or weighing), the max. possiblechuckdiameter(measure)as well as themax. possible speed ofthe machine. In order to reduce the possi­ble impact force to the permissible value, the permissible mass and RPM must be determined (e.g. enquiry at the machine manufacturer) and then the max. RPM of the machine restricted (if required). However, the parts of the clamping set (e.g. top jaws, workpiece supports, face clamping claws etc.) should be designed to be as light as possible.

3.Clamping other/ additional workpieces Special clamping sets designed for use with this clamping fixture (jaws, clamping inserts, locating fixtures, aligning

Personnel lacking any experience in the handling of clamping fixtures are at particular risk of sustaining injury due to incorrect handling and usage, such injuries emanating in particular from the clamping movements and forces involved during setup work. Clamping fixtures should therefore only be used, set up or repaired by personnel specially trained or instructed for this purpose and / or who have long years of experience. Chuck functionality should be tested after mounting prior to commissioning. Two important points are:

Clamping force: The clamping force specified for the clamping medium (+15%) should be achieved at max. actuation force / pressure.

Stroke monitoring: The clamping piston stroke should have a safety range in the front and rear end position. The machine spindle should only start if the clamping piston has passed through the safety range. Only limit sensors should be used for monitoring the clamping distance, and these should meet the requirements for safety limit sensors specified in VDE 0113/12.73 Section 7.1.3. II.Injury risks

This module can, for technical reasons, consist in part of individual components with sharp edges and corners. Any tasks involving this module should be carried out with extreme care to prevent risks of injury! 1. Integrated energy storage Moving parts which are pretensioned with pressure springs, tractive springs and other springs, or other flexible elements, are a potential source of risk, due to the intrinsic energy stored. Underestimation of this can lead to serious injury caused by uncontrolled, flying parts being propelled through the air. This stored energy must be dissipated before work can be continued. Clamping fixtures which are to be dismantled should be inspected for such sources of danger with the assistance of the respective assembly drawings.

The fixture should be dismantled by authorised ROHM personnel if it should prove impossible to "safely" dissipate this stored energy.

2.Maximum permissible speed The max. permissible speed may only be set with applied max. actuation force and clamping chucks which are functioning perfectly. Failure to observe this basic principle can lead to a loss of residual clamping force and, conse quently, workpieces being thrown out of the chuck and the risk of injury associated with this. The clamping fixture should only be used at high speeds under an adequately-dimensioned safety guard.

3. Exceeding the permissible speed This equipment is intended for revolving operation. Centrifugal forces created by excessive speed and / or peripheral speed can result in individual parts loosening and becoming potential sources of danger for personnel or objects in the near vicinity. In addition to this, clamping media which are only designed for use at lower speeds but are operated at high speeds can result in unbalance which adversely affects safety and the machining results achieved. Operation at speeds higher than those permit­ted for these units is prohibited for the above-mentioned reasons. The max. speed and actuation force / pressure are engraved on the body and should not be exceeded. This means that the max. speed of the machine being used should not exceed that of the clamping fixture