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Instructions - Application Guide Safety handwheels |
According to the safety regulations, handwheels must be secured to the shafts in such a way that during mechanical drive they do not rotate. These safety handwheels comply with this requirement.
| Procedure: By axial displacement of the wheel (pushing or pulling) two serrated wheel rims are engaged. The wheel is now positively keyed to the shaft. When the wheel is released, it automatically disengages. |
The same handwheel and coupling attachment can be arranged so as to require either a pushing or pulling action to engage. Greater security against accident is afforded by the 'pulling' arrangement; the wheel cannot be engaged by inadvertent pressure.
Our standard Safety Handwheels are available in aluminium, with a keyway, with or without revolving handle.
Originally intended for only a limited range of applications, de-coupling safety handwheels are nowadays applied to an extremely wide range of machines and requirement. In order to ensure the utmost security against accidents, the following guide lines are offered; we can, however, not accept any liability for any possible consequential damage which may be caused through the use of our coupling attachments.
1. Safety handwheels with friction bearing (coupling attachment GN 000.4)
Model D (with handpiece)
The range of application of these handwheels is limited to relatively low shaft velocities or higher velocities of only short duration (e. g. lead-screws for milling machines with fast traverse speed). A very high risk of pollution (grinding dust) can limit its scope still further.
Should the decoupled handwheel be put deliberately into motion in the same direction as the revolving shaft, the handwheel will tend to turn continuously due to bearing friction. At higher handwheel speeds this could lead to vibration caused by the rotating mass of the handle and create a certain danger.
Model A (without handpiece)
Due to the absence of a handle, admittedly this gives these wheels a tendency to turn, but this does not create any danger because minimal contact holds them stationary. For this reason, these safety wheels can be used with appreciably higher speeds. The bearing load is negligible. At high velocity, however the unbalanced handwheel could cause vibration
Lubrication at regular intervals is in every case a pre-requisite for troublefree functioning of the friction "bearing coupling attachments.
2. Safety handwheels with needle bearings (coupling attachment GN 000.5)
In principle the details specified under para 1 will also apply to these safety handwheels.
The needle bearings offer a great advantage over friction bearings through lower friction and they are less prone to break down through lack of lubrication at higher velocities.
The increased bearing length and lower friction (bearing surface is hardened) as well as the finer teeth make it in addition easier to engage the handwheels.
3. Safety handwheels with stationary bearing flange GN 327
These handwheels lend themselves for use on very high revolving shafts and continuous operation. Further information on request.
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