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1、BRITISH STANDARD BS 857:1967 Incorporating Amendments Nos. 1, 2, 3, 4 and 5 Specification for Safety glass for land transport ICS 03.220.01; 81.040.30 ? CONFIRMED SEPTEMBER 1990 Licensed Copy: London South Bank University, London South Bank University, Mon Jul 16 04:17:26 GMT+00:00 2007, Uncontrolle
2、d Copy, (c) BSI This British Standard, having been approved by the Glass Industry Standards Committee and endorsed by the Chairman of the Chemical Divisional Council, was published under the authority of the General Council on 30 June 1967 BSI 2007 First published June 1939 First revision November 1
3、949 Second revision April 1954 Third revision (Parts 1 and 2) September 1964 Fourth revision June 1967 The following BSI references relate to the work on this standard: Committee reference GLC/13 Draft for comment 66/18256 ISBN 978 0 580 59376 5 Co-operating organizations The Glass Industry Standard
4、s Committee, under whose supervision this British Standard was prepared, consists of representatives from the following scientific and industrial organizations: British Glass Industry Research Association* Glass Manufacturers Federation Society of Glass Technology* University of Sheffield (Departmen
5、t of Glass Technology) The organizations marked with an asterisk in the above list, together with the following, were directly represented on the committee entrusted with the preparation of this British Standard: Automobile Association British Plastics Federation Chief Fire Officers Association Flat
6、 Glass Manufacturers Association Ministry of Technology Ministry of Transport Ministry of Transport Road Research Laboratory Society of Motor Manufacturers and Traders Ltd. An individual manufacturer Amendments issued since publication Amd. No.Date of issueComments 1088January 1973 3402September 198
7、0 3547January 1981 3548February 1981Indicated by a sideline in the margin 1722631 July 2007A.2 Apparatus “circular slit . . .” changed to “inner diameter 3.33 cm” to align with Figure 4. BS 857:1967 Licensed Copy: London South Bank University, London South Bank University, Mon Jul 16 04:17:26 GMT+00
8、:00 2007, Uncontrolled Copy, (c) BSI BS 857:1967 BSI 2007i Contents Page Co-operating organizationsInside front cover Forewordiii 1General clauses, and optical requirements for windscreens1 1.1Scope1 1.2Definitions and general requirements1 1.3Optical requirements2 2Requirements specific to toughene
9、d safety glass2 2.1Properties and quality2 2.2Thickness3 2.3Marking4 2.4Sampling and acceptance4 2.5Uniformity test4 2.6Fragmentation test5 2.7Visual transmission11 3Requirements specific to laminated safety glass11 3.1Properties and quality11 3.2Thickness11 3.3Marking11 3.4Sampling and acceptance12
10、 3.5Light stability test12 3.6Boil test13 3.7Fracture and adhesion test13 3.8Impact test for high performance laminates14 4Requirements specific to toughened glass for use only in railway rolling stock16 4.1General16 4.2Flatness16 4.3Tong marks16 4.4Light transmission16 4.5Assessment of visual appea
11、rance17 Appendix A Test for optical deviation18 Appendix B Test for distortion of vision18 Appendix C Test for visual transmission19 Appendix D Apparatus required for uniformity test19 Appendix E Notes on fragmentation test19 Appendix F Apparatus for fracture and adhesion test and impact test19 Appe
12、ndix G Optical characteristics of windscreens20 Figure 1A Idealized fracture pattern of small-zone windscreen (Type Z)21 Figure 1B, C and D Idealized fracture patterns of wide-zone windscreens (Types Z1 and Z2)22 Figure 2A Primary vision area for optical tests on windscreens23 Figure 2B Primary visi
13、on areas for optical tests on divided windscreens24 Figure 3 Particle count and size determinations25 Figure 4 Apparatus for optical deviation test27 Figure 5 Diagram of typical polariscope28 Licensed Copy: London South Bank University, London South Bank University, Mon Jul 16 04:17:26 GMT+00:00 200
14、7, Uncontrolled Copy, (c) BSI BS 857:1967 ii BSI 2007 Page Figure 6 Frame for fracture and adhesion test and impact test29 Figure 7 Deviation and separation of images due to curvature30 Figure 8 Deviation and separation of images due to wedge30 Figure 9 Relationship between optical characteristics o
15、f a curved windscreen31 Table 1 Conditions of acceptance for windscreens (optical requirements)2 Table 2 Limits of thickness for heat-treated safety glass3 Table 3 Limits of thickness usual for heat-treated safety glass for the automobile industry3 Table 4 Summary of requirements for fragmentation t
16、ests for toughened safety glass8 Table 5 Conditions of acceptance for toughened safety glass10 Table 6 Limits of thickness for laminated safety glass11 Table 7 Conditions of acceptance for laminated safety glass15 Licensed Copy: London South Bank University, London South Bank University, Mon Jul 16
17、04:17:26 GMT+00:00 2007, Uncontrolled Copy, (c) BSI BS 857:1967 BSI 2007 iii Foreword This standard makes reference to the following British Standard: BS 354, Recommendations for photometric integrators. This British Standard was first published in 1939 and revised editions were published in 1949 an
18、d 1954. A major amendment to the 1954 edition was issued in 1961 when the zoned type of toughened glass windscreen was introduced. This was followed in 1964 by a separate publication of Parts 1 and 2 covering, for the first time, optical requirements for all windscreens and also a further revision o
19、f the toughened glass specification including both uniform and non-uniform wide-zone windscreens. Minor editorial changes are not tagged, the amendments in this issue are described in the amendment table. The representative technical committee which is responsible for this standard under the authori
20、ty of the Glass Industry Standards Committee, continued its revision work on the laminated glass sections of the 1954 specification and in particular modified these to include a more severe impact test for windscreens, thus ensuring that only so-called “high performance” laminates will be used for t
21、his purpose. At the same time the impact requirements for all laminated glass have been made more stringent by increasing from 16 ft (4.9 m) to 30 ft (9.15 m) the height from which the ball is dropped in the fracture and adhesion test. A light stability test is included, in which the visual transmis
22、sion of the laminate is measured both before and after exposure to ultraviolet radiation. The toughened glass specification has also been reviewed in the light of technical advances made since 1964 and the following main changes are incorporated in the new edition. 1) Only zoned glass is now include
23、d for windscreens as it is felt that the uniformly toughened glass, which may obscure the drivers vision if it fractures, should no longer be used for windscreens. NOTE By amendment in January 1973, the application of the above provision regarding zoned glass was limited to windscreens for the gener
24、al run of road vehicles, and it was recognized that uniformly toughened glass is acceptable for the windscreens of railway locomotives and of relatively slow-moving agricultural and industrial tractors. 2) For purposes other than windscreens, provision has been made for the use of glass toughened by
25、 chemical treatment, instead of heat treatment, provided it meets the requirements of the standard. 3) The requirements for zoned windscreens have been made more stringent by defining the maximum size of individual particles after fracture and the test procedure for the non-uniform zone glass (Type
26、Z2) has been modified so as to encourage the manufacture of windscreens which give better visibility in the event of fracture. In keeping with the general changeover of the British industry to the metric system, dimensional requirements have been given in metric units throughout this revision, with
27、the corresponding inch-lb units given also for information. The committee has studied the latest standards and proposals for safety glass in vehicles, prepared in the USA and on the continent of Europe, and where considered appropriate the specification requirements and test procedures of this stand
28、ard have been harmonized with such overseas standards. The testing equipment and procedure described in Appendix A to Appendix F are substantially unchanged from the earlier editions, except that Appendix F now covers the requirements of the more severe impact test referred to above. Data are also g
29、iven in Appendix G, for information only, indicating the effect of windscreen design features (e.g. rake angle and designed curvature) on the optical characteristics. Licensed Copy: London South Bank University, London South Bank University, Mon Jul 16 04:17:26 GMT+00:00 2007, Uncontrolled Copy, (c)
30、 BSI BS 857:1967 iv BSI 2007 Contractual and legal considerations This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. Compliance with a British Standard cannot confer immunity from legal obligations. Summary of p
31、ages This document comprises a front cover, an inside front cover, pages i to iv, pages 1 to 31 and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover. The BSI copyright n
32、otice displayed in this document indicates when the document was last issued. Licensed Copy: London South Bank University, London South Bank University, Mon Jul 16 04:17:26 GMT+00:00 2007, Uncontrolled Copy, (c) BSI BS 857:1967 BSI 20071 1 General clauses, and optical requirements for windscreens 1.
33、1 Scope This British Standard specifies requirements and tests for flat and curved safety glass for land transport, of thicknesses from 2 mm (0.08 in) to 13 mm (0.5 in). 1.2 Definitions and general requirements For the purposes of this British Standard the following definitions apply. Mandatory gene
34、ral requirements, where applicable, are also given. 1.2.1 safety glass (general definition) a glass which, if fractured, is less likely to cause severe cuts or serious physical injury than ordinary glass 1.2.2 safety glass for windscreens a glass as defined above which in addition does not cause any
35、 appreciable distortion of objects ahead of the vehicle seen through it; and which, if fractured, permits a sufficient view ahead to enable the driver to control the vehicle whilst bringing it to rest 1.2.3 toughened safety glass (also known as tempered safety glass) glass which has been converted t
36、o a safety glass by subjection to a process of pre-stressing so that, if fractured, it disintegrates into small pieces. In general, its liability to fracture under the action of external forces or changes of temperature is greatly reduced by this process. Unless otherwise specified the pre-stressing
37、 is substantially uniform over the whole area of the glass pre-stressing may be carried out by heating and rapid cooling or by chemical treatment 1.2.4 heat-treated safety glass for windscreens heat-treated safety glass having a zone of modified heat treatment in which the fragmentation, if the glas
38、s is fractured, comprises sufficient pieces of larger size than elsewhere to afford better vision through the zone than through the remainder of the glass at least the marginal part of the glass, of a width not less than 6 cm (2.5 in) shall disintegrate upon fracture into small pieces. The dimension
39、s and location of the zone shall be agreed between the vehicle maker and the manufacturer of the safety glass; even in the case of half-screens the dimensions of the zone shall be not less than 40 cm (16 in) 15 cm (6 in) three types of zoned windscreen are covered by this British Standard: a) Unifor
40、m small zone, Type Z, in which the stresses in the glass are substantially even throughout a zone in front of the driver (see Figure 1A). b) Uniform wide zone, Type Z1, in which the stresses in the glass are substantially even throughout a zone extending across the greater part of the windscreen (se
41、e Figure 1B). c) Non-uniform wide zone, Type Z2, in which the stresses in the glass vary in intensity over the zone so that, if the glass is fractured, alternate areas break into fine and coarse particles respectively. NOTE Uniformly toughened safety glass complying with the requirements of Section
42、2 of this standard is permitted for the windscreens of railway locomotives and of relatively slow-moving agricultural and industrial tractors capable of a speed not exceeding 20 mile/h (32.2 km/h) on level ground. in general, the alternate areas shall be arranged in a regular pattern over the zone a
43、nd the stresses in corresponding areas shall be substantially the same (see Figure 1C and Figure 1D) 1.2.5 laminated safety glass a product made of two or more pieces of glass firmly united to, and alternating with, one or more pieces of reinforcing material (known as “interlayer” or “interleaf”). F
44、racture does not cause the glass to separate from the interlayer to any substantial extent and in general the product does not break into large fragments 1.2.6 primary vision area that part of the windscreen through which the principal field of view is obtained (see Figure 2A and Figure 2B) NOTE Fig
45、ure 2A excludes from the primary vision area a band round the edge of the glass 6 cm (2.5 in) wide at top and bottom and 9 cm (3.5 in) wide at the sides. Compliance with the optical requirements in 1.3 implies the avoidance of sharp curvatures throughout the primary vision area. 1.2.7 consignment th
46、e whole of the safety glass delivered at any one time in connection with an order or contract Licensed Copy: London South Bank University, London South Bank University, Mon Jul 16 04:17:26 GMT+00:00 2007, Uncontrolled Copy, (c) BSI BS 857:1967 2 BSI 2007 Table 1 Conditions of acceptance for windscre
47、ens (optical requirements) 1.3 Optical requirements 1.3.1 General. The requirements detailed in 1.3.2 to 1.3.4 are specified only for windscreens and apply only to the primary vision area of the windscreen as defined in 1.2.1 6). Since this area necessarily varies, with different models of land tran
48、sport vehicle according to the rake angle of the windscreen, seated height, distance from the windscreen and lateral placement of the driver, the vehicle manufacturer should define for each model the “eye position” to which the primary vision area is related1). 1.3.2 Optical deviation. When the wind
49、screen is tested in accordance with Appendix A: 1) Using the “ring and spot” target, there shall be no displacement of the secondary image2) beyond the point of tangency of the central spot image with the inside edge of the circle; this limits the secondary image separation to a maximum of 15 minutes of arc. 2) Alternatively, using the “ring” target, the primary and secondary images of the circle shall either overlap or touch; this also limits the s