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OSHA Regulations - Selected Passages
The following are selected sections from the OSHA 1910.217 standard for Mechanical Power Presses concerning light curtain presence sensing devices, machine controller design and other information. Interpretations are provided with permission from the Precision Metalforming Association (PMA).

Omron Scientific Technologies, Inc. provides the information for user reference only and makes no claim regarding a specific recommendation of any organization, the accuracy, or effectiveness for a specific application. These excerpts are not intended to be used as a replacement for the complete OSHA standards.

OSHA 1910.217(b)(7) Part Revolution Clutch, Controls
(7) Machines using part revolution clutches.
(i) The clutch shall release and the brake shall be applied when the external clutch engaging means is removed, deactivated, or de-energized. (ii) A red color stop control shall be provided with the clutch/ brake control system. Momentary operation of the stop control shall immediately deactivate the clutch and apply the brake. The stop control shall override any other control, and reactuation of the clutch shall require use of the operating (tripping) means which has been selected.

PMA Interpretation:
(7)(ii) Refers to part revolution clutch only. (iii) A means of selecting of, “Inch,” Single Stroke, and Continuous (when the continuous function is furnished) shall be supplied with the clutch/brake control to select type of operation of the press. Fixing of selection shall be by means capable of supervision by the employer. PMA Interpretation: (7)(iii) Control modes cannot be readily changed by the press operator without administrative supervision. A key lock switch is a convenient way of providing supervisory control if keys are not available to operators.

OSHA 1919.217(b)(13) Control Reliability

(13) Control reliability. When required by paragraph (c) (5) of this section, the control system shall be constructed so that a failure within the system shall not prevent the normal stopping action from being applied to the press when required, but does prevent initiation of a successive stroke until the failure is corrected. The failure shall be detectable by a simple test, or indicated by the control system. This requirement does not apply to those elements of the control system which have no effect on the protection against point of operation injuries.

PMA Interpretation: (13) The main requirements for control reliability are: 1. That no failure prevent the stopping action from occurring, and 2. That no successive stroke can be initiated until the failure is cleared. There requirements impose a need for self-checking/selfmonitoring such that any failure will be detected and thus subsequent strokes will be prohibited. When the above requirements are met the requirement for indication or simple test is fully provided. The best of all indication of failure is the press won’t run. Also the tests to detect a failure are done automatically. Care must be exercised when evaluating a press control system in meeting this requirement. The control system must be considered to be all the elements covered in the definition for “Control System” which effect the point of operation.

OSHA 1910.217(b)(14) Brake System Monitoring
(14) Brake system monitoring. When required by paragraph (c)(5) of this section, the brake monitor shall meet the following requirements:
(i) Be so constructed as to automatically prevent the activation of a successive stroke if the stopping time or braking distance deteriorates to a point where the safety distance being utilized does not meet the requirements set forth in paragraph (c)(3)(iii)(e) or (c)(3)(vii)(c) of this section. The brake monitor used with the Type B gate or movable barrier device shall be installed in a manner to detect slide top-stop overrun beyond the normal limit reasonably established by the employer.
(ii) Be installed on a press which indicates when the performance of the braking system has deteriorated to the extent described in paragraph (b)(14)(i) of this section; and (iii) Be constructed and installed in a manner to monitor brake system performance on each stroke. PMA Interpretation:
  • Brake Monitor must check the continued effectiveness of the braking system.
  • The Brake Monitor is not in itself a point of operation device.
  • It must be used on a part revolution clutch press in conjunction with a two hand control, presence sensing or Type B gate (movable barrier device), when these are used as point of operation safety device with hand-in-the-die feeding.
  • The Brake Monitor is part of the press control system and must inhibit further stroking of the press when braking action exceeds predetermined limits.
  • The predetermined limits must be equal to or less than the stopping time used in setting the safety distance.
  • The Brake Monitor as well as the press control must meet the “control reliability requirements” as specified in (1910.217)(b.13).

OSHA Table 0-10. This table shows the distances that guards shall be positioned from the danger line in accordance with the required openings. (from OSHA 1910.217)

OSHA 1910.217(c) Safeguarding the Point of Operation

(1) General Requirements.
(i) Its shall be the responsibility of the employer to provide and insure the usage of “point of operation guards” or properly applied and adjusted point of operation devices on every operation performed on a mechanical power press. See Table 0 – 10.
(ii) The requirement of subdivision (i) of this subparagraph shall not apply when the point of operation opening is one-fourth inch or less.

See Table 0 – 10.

OSHA 1910.217 (c)(3) Point of Operation Devices

(i) Point of operation devices shall protect the operator by:
(a) Preventing and/or stopping normal stroking of the press if the operator’s hands are inadvertently placed in the point of operation. PMA Interpretation: Presence sensing device.

OSHA 1910.217 (C)(3)(iii) Presence Sensing Device

(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 operation’s hand or other part of his body is within the sensing field of the device during the downstroke of the press slide. PMA Interpretation: (c)(3)(i)(a) Refers to the functional requirement of a presence sensing device which prevents and/or stops normal stroking of the press.
(a) The device may not be used on machines using full revolution clutches.
(b) The device may not be used as a tripping means to initiate slide motion except when used in total conformance with paragraph (h) of this section. PMA Interpretation: (Note: paragraph (h) refers to very specialized and specific requirements for Presence Sensing Device Initiation.)
(c) The device shall not 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. PMA Interpretation: When failure occurs the best indication is the press won’t run.
(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. PMA Interpretation: Top of stroke is the point at which muting shall cease as it is not possible to set a point on the downstroke as the exact position where the hazard of die closing starts.
(f) Guards shall be used to protect all areas of entry to the point of operation not protected by the presence sensing device. PMA Interpretation: (3)(iii)(f) Great care must be taken to assure that no access to the die area exists unguarded.

OSHA 1910.217 (c)(3)(5) Additional Requirements for Safeguarding

Where the operator feeds or removes parts by placing one or both hands in the point of operation, and a two hand control, presence sensing device of Type B gate or movable barrier (on a part revolution clutch) is used for safeguarding.
PMA Interpretation:
This paragraph tells the condition under which a brake monitoring system is required after November 1, 1975.

(i) the employer shall use a control system and a brake monitor which comply with paragraphs (b) (13) and (14) of this section. This requirement shall be complied with by November 1, 1975. PMA Interpretation: (b)(13) Control reliability. (b)(14) Construction requirements. (ii) the exception in paragraph (b)(7)(v)(d) of this section for two hand controls manufactured and installed before August 31, 1971, is not applicable under this paragraph (c)(5);

PMA Interpretation:
When brake monitoring is required, two-hand controls manufactured and installed before August 31, 1975, must be designed to require release of all operator’s hand controls before an interrupted stroke can be resumed.
(iii) the control of air clutch machines shall be designed to prevent a significant increase in the normal stopping time due to a failure within the operating valve mechanism, and to inhibit further operation if such failure does occur, where a part revolution clutch is employed. The exception is paragraph (b)(7)(xi) of this section for controls manufactured and installed before August 31, 1971, is not applicable under this paragraph (c)(5).
PMA Interpretation: When a brake monitor is required this paragraph removes the exception on valve mechanism manufactured or installed before August 31, 1971. All machines regardless of age used for hands-in-the-die-feeding or unloading and using a two hand control device, presence sensing device or type B gate must utilize a dual self-checking air valve.

OSHA 1910.217(e) Inspection, Maintenance, and Modification of Presses

(1) Inspection and maintenance records.
(i) It shall be the responsibility of the employer to establish and follow a program of periodic and regular inspections of his power presses to insure that all their parts, auxiliary equipment, and safeguardings are in a safe operating condition and adjustment. The employer shall maintain records of these inspections which includes the date of inspection, the signature of the person who performed the inspection, and the serial number, or other identifier of the power press that was inspected. PMA Interpretation: Records of clutch and brake will be weekly. Other inspections are periodic subject to time factor determined by employer.
(ii) Each press shall be inspected and tested no less than weekly to determine the condition of the clutch/brake mechanism, antirepeat feature and single stroke mechanism. Necessary maintenance or repair or both shall be performed and completed before the press is operated. The employer shall maintain records of these inspections and the maintenance work performed. These requirements do not apply to those presses which comply with paragraphs (b)(13) and (14) of this section. The employer shall maintain a certification record of inspections, test, and maintenance work which includes the date of inspection, the signature of the person who performed the inspection, test or maintenance; and the serial number or other identifier of the press that was inspected, tested or maintained.
PMA Interpretation: If brake monitoring system is installed, weekly inspection and records are not required for clutch/brake mechanism. Other parts of the press will require periodic inspections and records.
(2) Modification. It shall be the responsibility of any person modifying a power press to furnish instructions with the modification to establish new or changed guidelines for use and care of the power press so modified.
(3) Training of maintenance personnel. It shall be the responsibility of the employer to insure the original and continuing competence of personnel caring for, inspecting , and maintaining power presses.
PMA Interpretation: PMA’s’s training material will assist you in meeting this requirement.

OSHA 1910.217(5)(c) Operation of Power Presses

(2) Instructions to operators. The employer shall train and instruct the operator in the safe method of work before starting work on any operation covered by this section. The employer shall insure by adequate supervision that correct operating procedures are being followed. PMA Interpretation: PMA’s new training manual for press operators will help you meet this requirement.
(3) Work area. The employer shall provide clearance between machines so that movement of one operator will not interfere with the work of another. Ample room for cleaning machines, handling material, work pieces, and scrap shall also be provided. All surrounding floors shall be kept in good condition and free from obstructions, grease, oil, and water.
PMA Interpretation: Good general housekeeping is always required.
(4) Overloading. The employer shall operate his presses within the tonnage and attachment weight ratings specified by the manufacturer.
PMA Interpretation: Check tonnage and weight of die at time of diesetting.