Test presses running in a continuous mode – AMETEK 1025 Foot & Palm Switches User Manual
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Chapter 3: Operating Instructions
Operating Manual
14
The Gemco Semelex II Safetimeter measures slide position, direction and velocity to
determine brake effi ciency stop time. The initiation of a stop can be made at almost
any reasonable point near mid-stroke (assuming the press is balanced), and will
accurately measure the stop time.
3.10: Test Presses Running in a Continuous Mode
Because the Safetimeter sends a release command to the Auto-Hand each time the
P/V transducer crosses the Control Start Point (CSP), a special method must be used
to test a press running in a continuous mode. Typically, this test is performed on the
press’s Emergency Stop (E-STOP) button or a presence sensor.
1.
Position the P/V transducer as described in Section 3.1: Placement of
Position/Velocity (P/V) Transducer.
2.
Set the CSP to initiate a stop at the 90 degree crankshaft position.
3.
Ready Auto-Hand to press the E-STOP button or interrupt the presence sensor
with Auto-Flag.
4.
Make the following Safetimeter switch settings:
Display
(as desired)
Timing Direction
TIME DOWN
Revolution
PART REV
5.
Press the Safetimeter power switch OFF.
6.
Start the press in continuous mode.
7.
Observe that the press is up to speed.
Checking the down and up stroke time should be done prior to making the down
stop time test. This is done by using the Safetimeter with Auto-Hand. The two-hand
control circuit will not generally do this. Typically, the simplest control that can do
this is the inch circuit. Auto-Hand can be used over this control for initiating a stop
anywhere in the stroke. The timing direction selector switch on the
Safetimeter is set for either down or up, whichever direction is being tested. Several
stops should be made in both directions, and an average in each direction should be
made. Readings taken in each direction should be close to the others made in that
direction. Erratic readings are reason to suspect a defective brake or control circuit
which should be repaired before proceeding.