Rockford Systems, LLC
1-800-922-7533 (U.S.A. only)
6
“MECHANICAL POWER PRESS SAFETY” BOOKLET
A copy of Booklet No. MPPS “Mechanical Power Press Safety” is available on request. This booklet is copied verbatim
from the Federal Register and contains all pertinent sections of the OSHA Regulations concerning power presses with
which an employer (user) must comply. The enclosed equipment must be installed, used and maintained to meet these
regulations. Specifically, any time a foot switch is used, a suitable point-of-operation guard or device must be used to
prevent bodily injury. Moreover, every press must be provided with point-of-operation safeguarding! If you are unfamiliar
with these detailed safety regulations that include proper safeguarding of the point of operation or how to calculate the
safety distance for light curtains or two-hand control, you may want to attend our regularly scheduled monthly seminars. To
obtain additional detailed information about these training seminars, please call, fax, email, or write. Our address, telephone
and fax numbers, and email address are on the front cover of this manual.
OSHA REGULATIONS AND ANSI STANDARDS
Electrical, pneumatic, or hydraulic equipment can never overcome a mechanical deficiency, defect or malfunction in the
machine. OSHA (Occupational Safety and Health Administration) has established certain regulations for employers (users) to
ensure that the machines used in their plants, factories or facilities are thoroughly inspected and are in first-class operating
condition before safeguards are installed.
Before installing a light curtain or two-hand control, be sure that the applicable OSHA Regulations and the ANSI (American
National Standards Institute) standards have been read and understood. For example, if a light curtain or two-hand control is
going on a mechanical power press (punch press) with a part revolution clutch, the following are the requirements from OSHA:
SUBPART O, 1910.217, (C)(3)(III) PRESENCE SENSING DEVICES
(iii) A presence sensing point of operation device shall protect the operator as provided in paragraph (c)(3)(i)(a) of this
section, and shall be interlocked into the control circuit to prevent or stop slide motion if the operator’s hand or other
part of his body is within the sensing field of the device during the downstroke of the press slide.
(a) The devices may not be used on machines using full revolution clutches.
(b) The devices may not be used as a tripping means to initiate slide motion, except when used in total conformance
with paragraph (h).
(c) The device shall be constructed so that a failure within the system does not prevent the normal stopping action from
being applied to the press when required, but does prevent the initiation of a successive stroke until the failure is
corrected. The failure shall be indicated by the system.
(d) Muting (bypassing of the protective function) of such device during the upstroke of the press slide, is permitted for the
purpose of parts ejection, circuit checking, and feeding.
(e) The safety distance (Ds) from the sensing field to the point of operation shall be greater than the distance determined
by the following formula:
(Continued on next page.)
SECTION 1—TABLE OF CONTENT
Stop-Time Measurement Device
Ds = 63 inches/second x Ts
Where: Ds = minimum safety distance (inches); 63 inches/second = hand speed constant;
and Ts = stopping time of the press measured at approximately
90° position of crankshaft rotation (seconds). (See chart on next page.)
Note: When using a light curtain, please add the response time of the light curtain to the above formula.
(f) Guards shall be used to protect all areas of entry to the point of operation not protected by the presence sensing device.
