AMETEK 1025 Foot & Palm Switches - Manual (Page 20)

Chapter 3: Operating Instructions
Operating Manual 16
The Safetimeter can aid in calculating safety distance of a full revolution clutch
press by measuring the time necessary to complete one revolution of the crankshaft.
Perform the following steps:
1. Set the FULL REV/PART REV switch to FULL REV.
2. Set the TIME UP/TIME DOWN switch to TIME UP.
3. Set the STOP TIME/SAFETY DISTANCE switch to STOP TIME.
4. Position the P/V transducer as described in Section 3.1: Placement of
Position/Velocity (P/V) Transducer.
5. Push the Safetimeter power switch to ON.
6. Cycle the press. The Safetimeter will begin counting when the ram begins to
travel down and will stop counting when the ram stops on the up stroke. The
Safetimeter will display the time for one stroke of the press.
NOTE: Do not set the STOP TIME/SAFETY DISTANCE switch to SAFETY DISTANCE.
The Safetimeter can not read safety distance for full revolution clutch presses.
3.12: Test Full Revolution Clutch Presses
Calculating the safety distance of a full revolution clutch press per OSHA 29 CFR
1910.217(c)(3)(viii)(c) is as follows:
Dm=63 inches/second x Tm; where:
Dm=Minimum safety distance (inches);
63 inches/second = hand speed constant:
and
Tm = the maximum time the press takes for die closure after it has been tripped
(seconds). For full revolution clutch presses with only one engaging point, Tm is
equal to the time necessary for one and one-half revolutions of the crankshaft.
For full revolution clutch presses with more than one engaging point, Tm shall
be calculated as follows:
Tm = [1/2 + (1 / Number of engaging points per revolution)] x time necessary to
complete one revolution of the crankshaft (seconds).