ISO/TS 19837:2018

Safety of machinery — Trapped key interlocking devices — Principles for design and selection

ISO/TS 19837:2018 specifies principles for the design, selection and application of trapped key interlocking devices and systems for machinery applications, independent of the type of energy used to control them or that they control. The requirements of this document apply to the safety related aspects of trapped key interlocking devices and systems. ISO 14119 always applies unless an exception is given in this document. ISO/TS 19837:2018 is intended to be used in conjunction with ISO 14119. ISO/TS 19837:2018 does not provide testing requirements. NOTE Documents addressing testing requirements can be found in the Bibliography.

Sécurité des machines — Dispositifs de verrouillage à clé captive — Principes de conception et sélection

General Information

• Status: Published
• Publication Date: 03-Apr-2018
• ICS: 13.110 - Safety of machinery
• Technical Committee: ISO/TC 199 - Safety of machinery
• Drafting Committee: ISO/TC 199/WG 7 - Interlocking devices
• Current Stage: 9020 - International Standard under periodical review
• Start Date: 15-Jul-2024
• Completion Date: 15-Jul-2024

Standards Content (Sample)

TECHNICAL ISO/TS
SPECIFICATION 19837
First edition
2018-03
Safety of machinery — Trapped key
interlocking devices — Principles for
design and selection
Sécurité des machines — Dispositifs de verrouillage à clé captive —
Principes de conception et sélection
Reference number
©
ISO 2018
© ISO 2018
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ii © ISO 2018 – All rights reserved

Contents Page
Foreword .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols and abbreviated terms . 4
5 Operating principles and typical forms of trapped key interlocking system .5
5.1 General . 5
5.2 Functional decomposition of a trapped key interlocking system . 8
5.2.1 Isolation control . 9
5.2.2 Intermediate transfer .12
5.2.3 Access control .13
6 General requirements for the design of Trapped Key interlocking device .13
6.1 General .13
6.2 Device architecture and positive mechanical action .13
6.3 Endurance/Strength .14
6.3.1 General.14
6.3.2 Resistance to shock and vibration .14
6.3.3 Mechanical life .14
6.3.4 Rotary actuators for access locks .14
6.3.5 Key retention .15
6.4 Systematics .15
6.5 Safety FMEA/FTA .15
6.6 Validating Performance Level .15
6.7 Design to minimize defeat .16
6.7.1 General.16
6.7.2 Scheme design for ease of use .16
6.7.3 Coded actuators .16
6.7.4 Reproduction of keys .16
6.8 Clearances and creepage distances .17
6.9 Isolation control .17
6.9.1 General.17
6.9.2 Direct mechanical action (Power interlocking) .17
6.9.3 Solenoid controlled switch .17
6.10 Access control .17
6.10.1 Escape release .17
6.10.2 Emergency release .18
6.10.3 Auxiliary release . .18
7 System configuration .18
7.1 General .18
7.2 Key coding .18
7.3 Key transfer plan .19
7.4 System selection .19
7.4.1 General.19
7.4.2 Isolation control .19
7.4.3 Intermediate transfer .19
7.4.4 Access control .19
8 Information for use .19
Annex A (informative) Examples of trapped key interlock devices .20
Annex B (informative) FMEA analysis — Typical failure modes for consideration in trapped
key systems .26
Annex C (informative) Safety functions and validation in accordance with ISO 13849-1 and
ISO 13849-2 .27
Annex D (informative) Selection of trapped key interlocking devices .29
Bibliography .30
iv © ISO 2018 – All rights reserved

Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/ patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation on the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the following
URL: www .iso .org/ iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 199, Safety of machinery.
TECHNICAL SPECIFICATION ISO/TS 19837:2018(E)
Safety of machinery — Trapped key interlocking devices —
Principles for design and selection
1 Scope
This document specifies principles for the design, selection and application of trapped key interlocking
devices and systems for machinery applications, independent of the type of energy used to control them
or that they control.
The requirements of this document apply to the safety related aspects of trapped key interlocking
devices and systems. ISO 14119 always applies unless an exception is given in this document.
This document is intended to be used in conjunction with ISO 14119.
This document does not provide testing requirements.
NOTE Documents addressing testing requirements can be found in the Bibliography.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 14119:2013, Safety of machinery — Interlocking devices associated with guards — Principles for
design and selection
ISO 13849-1, Safety of machinery — Safety-related parts of control systems — Part 1: General principles
for design
ISO 13849-2, Safety of machinery — Safety-related parts of control systems — Part 2: Validation
IEC 60947-1:2008, Low-voltage switchgear and controlgear — Part 1: General rules
3 Terms and definitions
For the purposes of this document, the foll
...