Ba-Nr.: 930.50.02 E
Edition: 03/96
4.0 Working with the
gripping force meter
13 / 18
4.0 Working with the gripping force meter
4.1 Preparation of the power chuck and machine
Testing of gripping force should always be carried out with the chuck set up as for the
current workholding task. In particular the gripping force meter should be positioned, if
possible, in the ridges of the top jaws which are used for each machining process.
This is especially important with high and wide top jaws which over-
hang the chuck. In such instances, even a chuck in good condition
regularly delivers lower gripping force readings than obtained when
chucking with short jaws. The reduced ratings to be expected with
such top jaws should be taken from the appropriate chuck Operating
Manual. For all FORKARDT chucks, this information is clearly dis-
played at the end of the relevant manual. For measurements with
other chucks, FORKARDT recommends consultation with the appro-
priate manufacturer.
Before testing begins, make sure that the workspindle of the machine
is blocked and that the chuck cannot be set in motion, even acciden-
tally.
Also make sure that there is no potential danger to the operator from
other parts of the machine like tools, tool holders, loading devices,
chip conveyors, protection devices etc., for example through unex-
pected movements or protrusions into the working area and other re-
strictions of the Operator's movements.
When taking readings on 6-jaw chucks the chuck must be in compen-
sating mode so that all tension bolts are evenly loaded. False readings
will otherwise result.
4.2 Preparation of the gripping force meter
The maximum gripping force of FORKARDT chucks can be found in the relevant Operating
Manual supplied with the chuck.
It must be checked that the expected gripping force of the chuck is inside
the permitted range of the gripping force meter ( see section 2.5 ).
In the case of non- FORKARDT chucks or lack of operational documents FORKARDT recom-
mends consultation with the appropriate manufacturer.
The meter should be set up for the number of jaws and gripping di-
ameter of the chuck to be tested by screwing in appropriate tension
and compression bolts. Tension bolts with rounded heads should al-
ways be screwed in last for contact with the chuck jaws. All extension
pieces must be screwed in tightly. For range of tension and compres-
sion bolts and fitting details see section 3.4.
A second set of tension and compression bolts is required for testing 6-jaw chucks. This is not
included in the standard package and can be ordered separately from your nearest FORKARDT
Operation or Representative ( see section 5.2 and 5.3 ).
Summary of Contents for SKM 1200
Page 19: ...Notes 1 19...
