Wintriss Shadow 8, Руководство пользователя

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Shadow 8 User Manual 1139300
Installation and Checkout 2-5
The OSHA safety distance formula as specified in OSHA 1910.217 is
Ds = K x Ts
where
Ds is the OSHA safety distance in inches
K is the OSHA-recommended hand-speed constant of 63 inches-per-second
Ts is the stopping time of the press in seconds
The hand-speed constant indicates how far you could theoretically move your hand and arm in
one second.
The stopping time Ts must be measured at approximately 90° of crankshaft rotation (or at
maximum velocity) and include all the following parameters:
•
Response time of the press control that activates the brake
•
Response time of the light curtain (see specifications in Table 1-1, page 1-13)
•
Response time of other devices involved in stopping the press
Since some increase in stop time can invariably be anticipated due to clutch/brake system
deterioration, a percentage factor must also be added to the actual measured stop time of your
press when determining the safety distance.
A factor of 20 percent is recommended for presses with brakes that are new or in good
condition. A 10-percent factor is recommended for presses with older brakes. Since the
stopping time for older brakes is longer due to wear, less time needs to be added.
An example of calculating the safety distance using the OSHA formula
The OSHA formula for calculating the safety distance is:
Ds = 63 x Ts
We will use a stop time of 0.190 seconds for this example. This includes the reaction time of
all devices noted above in signaling the press to stop except the response time of the light
curtain. Next we will add the Shadow 8 response time and the braking percentage factor. We
will use a worst-case response time of .059 seconds for a Shadow 8 system with a protected
length of between 172 in. and 202 in. We will assume that our brakes are new and add 20% to
the stop time measurement (.20 x 0.190 = .038). Then:
Ts = .190 sec. + .059 sec. + .038 sec.
Shadow 8 response time braking factor
Ts = .287 sec.
Wintriss recommends that you use the American National Standards Institute formula for
calculating safety distance because it contains more factors, allowing you to calculate the safety
distance more precisely. The ANSI formula is explained in the next section (see page 2-6).
NOTICE