Table of contents
3QLCLM
Edition: 04/2014
21
•
When inserting the work pieces into the power chuck, one top jaw must always be placed at
the bottom so that jamming of the work piece between two top jaws is avoided.
•
When the work piece is inserted, the travel of the top jaws should be 3 mm or less. Design
top jaws in such a way that the jaw travel required to reach the gripping position is not more
than 3 mm.
•
Check the strength of the jaw mounting bolts. Recalculate the tensile strength (static and
dynamic). Use only good quality bolts of grade 10.9 to DIN 267!
•
For external clamping, arrange the mounting bolts as far as possible to the inside!
4.5 General safety instructions
•
A chucking pressure monitor must be provided to ensure that a minimum chucking pressure is
available.
•
The pressure monitor must be set and then locked to prevent any further adjustment so that
the machine can only be started when the chucking pressure exceeds an adequate minimum
value
•
The pressure at the clamping cylinder must be adjusted such that the max. permissible
actuation force of the power chuck is not exceeded.
•
The test regulations of the industrial safety authority demands that not only a pressure monitor
but also a stroke monitor is provided for the actuating cylinder. The stroke monitor must ensure
that the spindle and feed drives cannot be started or are automatically stopped if the power
chuck is opened or the actuating cylinder reaches the end of its stroke.
•
The lathe spindle must be prevented from starting when the power chuck is either fully open or
fully closed as the lathe will be stopped by the safety limit switches when the chuck is in its limit
positions. The machine spindle must not start until the chucking pressure in the actuating
cylinder has been built up and the power chuck has gripped within its permissible working
range.
•
In the event of failure of the hydraulic power supply, a signal must be triggered to stop the
spindle and the work piece must remain securely gripped until the spindle has come to a
standstill.
