1、BRITISH STANDARD BS 448-1:1981 IEC 67:1966 IEC 67A:1966 IEC 67B:1969 IEC 67C:1970 IEC 67D:1977 IEC 67E:1986 Incorporating Amendment No. 1 Dimensions of electronic tubes and valves Part 1: IEC dimensions UDC 621.38 181BS448-1:1981 This British Standard, having been prepared under the directionof the
2、Electronic Components Standards Committee, was published underthe authority of the Executive Board and comes intoeffect on 30April 1981 BSI 05-2000 First published1953 First revision 1981 The following BSI references relate to the work on this standard: Committee reference ECL/5 Draft for comment 79
3、/21173 DC ISBN 0 580 11619 0 Cooperating organizations The Electronic Components Standards Committee, under whose direction this British Standard was prepared, consists of representatives from the following: British Electrical and Allied Manufacturers Association (BEAMA) Electricity Supply Industry
4、in England and Wales Electronic Components Industry Federation* Electronic Engineering Association Institution of Electronic and Radio Engineers* Ministry of Defence* National Supervising Inspectorate* Post Office Society of British Aerospace Companies Limited Telecommunication Engineering and Manuf
5、acturing Association (TEMA) The organizations marked with an asterisk in the above list, together with the following, were directly represented on the Technical Committee entrusted with the preparation of this British Standard: Scientific Instrument Manufacturers Association Services Electronic Part
6、s Committee United Kingdom Atomic Energy Authority Amendments issued since publication Amd. No. Date of issue Comments 5998 September 1992 Indicated by a sideline in the marginBS448-1:1981 BSI 05-2000 i Contents Page Cooperating organizations Inside front cover National foreword ii Recommended pract
7、ice for the preparation of drawings for inclusion in IEC Publication 67 1 1 Scope 1 2 General rules 1 3 Base drawings 2 4 Outline drawings 4 Table I 5 Table II 6 Table III 6 Inter-conversion and rounding off of inch and millimetre dimensions 7 1 Original units 7 2 Toleranced dimensions 7 3 Untoleran
8、ced dimensions 7 4 Conversion of inches into millimetres 8 Table I 8 5 Conversion of millimetres into inches 9 Table II 9 Appendix 10 1 Tables for conversion from inches into millimetres 10 2 Tables for conversion from millimetres into inches 12 Part I: Bases 13 Quick reference guide to pin numbers
9、and pin circle diameters for various bases 14 List of drawings 16 General 18 Explanation regarding reference letters on drawings 21 Part II: Outlines 131 List of drawings 132 General 133 Explanation regarding reference letters on drawings 134 Part III: Caps 196 List of drawings 197 General 198 Part
10、IV: Special gauges for cathode-ray tubes 208 List of drawings 209 General 210 Additions to the lists of national codes appearing on the standard sheets of Publication 67 228 National appendix A United Kingdom coded bases, coded reference line gauges for CRTs and coded caps 230BS448-1:1981 ii BSI 05-
11、2000 National foreword This Part of this British Standard has been prepared under the direction of the Electronic Components Standards Committee and is identical with IECPublication 67:1966 (2nd edition) “Dimensions of electronic tubes and valves”, together with the matter given in Supplements67A, 6
12、7B, 67C, 67D and67E, which were issued between1966and1986 by the International Electrotechnical Commission (IEC). This standard is being issued in two Parts and supersedes BS448-1and BS448-2, published in1953, both of which will be withdrawn on the publication of Part2. Part 2will comprise data shee
13、ts for bases, top caps and gauges for electronic tubes not already included in Part1and for which there is a requirement in the United Kingdom. It is the intention eventually to withdraw, or transfer to Part1, those data sheets at present included in Part2, which will then itself be withdrawn. This
14、revision of BS448is necessary as IEC67has been adopted as a harmonized document (HD146) by CENELEC. Terminology and conventions. The text of the International Standard has been approved as suitable for publication, without deviation, as a BritishStandard. Some terminology and certain conventions are
15、 not identical with those used in British Standards; attention is especially drawn to the following. Wherever the word “publication” is used, referring to this standard, it should be read as “Part1of this standard”. In the table of conversion from millimetres to inches in the inter-conversion and ro
16、unding off of inch and millimetre dimensions, the comma is used as a decimal marker. In British Standards it is current practice to use a full point on the baseline as the decimal marker. Cross-references. In PartI “Bases”, the following International Standard is referred to in the text. The corresp
17、onding British Standard is as follows: Textual error. When the text of the International Standard was adopted as a British Standard, it was noted that in Part III Caps, there was no General clause, although it was shown in the contents list. This omission has been brought to the attention of the IEC
18、 and has been corrected in this British Standard. Additional information. Complete pages of French text have been deleted. Pages that contain part English and part French, irrespective of the form of layout used, have been reproduced in their entirety. A list of United Kingdom coded bases, caps and
19、reference line gauges is attached as a national appendix to this standard. It indicates in which Part of the standard the individual bases will be found, but it is not part of IEC Publication67. Scope. For the purposes of this British Standard the scope is detailed in clause1 (page1) together with t
20、he paragraphs headed “Scope” in the “General” sections of Parts I, II, IIIandIV. For convenience the scope can be summarized as follows: “This standard specifies the dimensions and necessary tolerances of electronic tube and valve bases and outlines, together with appropriate gauges, and also specif
21、ies the dimensions of valve caps. This standard also includes recommended dimensions for special gauges for cathode ray tubes, and the recommended practice for the preparation of drawings included in this standard.” ISO R 370:1964 Conversion of toleranced dimensions from inches intomillimetres and v
22、ice versa BS 2856:1973 Precise conversion of inchand metric sizes on engineeringdrawingsBS448-1:1981 BSI 05-2000 iii Basic rules for insertion and deletion of drawings in IEC Publication 67. 1) Only drawings which have the support of at least two countries (the originator and one other) will be cons
23、idered for insertion in IEC Publication67. 2) The deletion of a drawing is prevented when one country opposes the proposal. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance
24、with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pagesitoiv, pages1to231 and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. Th
25、is will be indicated in the amendment table on the inside front cover.iv blankBS448-1:1981 BSI 05-2000 1 Recommended practice for the preparation of drawings for inclusion in IECpublication 67 1 Scope This text gives recommended practice for the preparation of drawings for inclusion in this Publicat
26、ion. 2 General rules 2.1 General layout 2.1.1 The drawing shall show all dimensions necessary to assure clearances and mating with auxiliary accessories. 2.1.2 The country of origin, code and name should be stated at the foot of each sheet. 2.1.3 When a drawing is re-issued because of modifications,
27、 the changes made should be indicated by arrows in the margin. The date of the revised issue and of the superseded issue should be stated. 2.1.4 Drawings need not be drawn to scale, but they should be roughly in proportion and, where necessary for clarity, an enlarged detail drawing should be used.
28、2.1.5 Angles should be indicated as follows: a) By quoting the value in degrees and minutes and seconds. Where this is not practical, the value should be quoted in fractions of degrees. b) Where it is self-evident that a number of angles are of equal value, the value of only one of those angles shou
29、ld be quoted. 2.1.6 The pitch circle should be shown by a dot and dashed line. 2.1.7 Fractional dimensions in inch originals should be avoided if possible. 2.2 Drawing The drawing shall include: 2.2.1 A suitable side-view. 2.2.2 Such additional views and details as are required to show special confi
30、gurations or appendages. 2.3 Dimensions Two types of dimensions may be on the drawing, namely: 2.3.1 Dimensions with tolerances to be used where they are necessary to ensure compatibility. The number of decimals quoted for dimensions for which maximum, nominal and minimum values are given should be
31、the same. 2.3.2 Untoleranced nominal dimensions which are given for general information or which are used in specifying true geometrical positions. For such nominal dimensions, no specific tolerance is to be inferred. 2.4 Values of dimensions 2.4.1 Numerical dimensions shall not be shown directly on
32、 the views; they will be shown in tabular form under the view and related to reference letters on the view itself. 2.4.2 All reference letters on the drawings should be in an upright position. 2.4.3 Single maximum or single minimum dimensions should be stated in decimals to such a number of places a
33、s it is considered adequate to express the degree of accuracy appropriate to the dimension, e.g.if measurement to the nearest0.001in is considered appropriate, the dimension should be expressed to the third decimal place, (for example 0.005in). If measurement to the nearest0.01in is sufficient, the
34、dimension should be expressed to the second decimal place (for example0.50in) and so on. Similar consideration should begiven to the number of decimal places necessary when an original dimension is expressed in millimetres. 2.4.4 The table will give dimensions in both inches and millimetres and the
35、original system used shall be stated immediately above the table.BS448-1:1981 2 BSI 05-2000 2.5 Notes shall be numbered and placed under the table of dimensions. This table shall have a “Note” column on the right-hand side and the note reference shall be placed opposite the dimension to which the no
36、te refers. 2.6 Third angle projection shall be used and this shall be stated on each drawing. 2.7 All drawings shall allow a space for the date of approval. 2.8 Inter-conversion of inch and millimetre dimensions shall be in accordance with this Publication. 3 Base drawings 3.1 Definitions 3.1.1 base
37、 drawing a drawing which includes the dimensional characteristics of the base required for compatibility with the socket and interchangeability of the tube or valve of which it is a part 3.1.2 base diameter the major or greater diameter of the base 3.1.3 locating guide that portion of the base speci
38、fically designed to position the tube or valve in the socket Examples: bayonet pin, spigot and key or keyway, index guide and similar devices. 3.1.4 datum line a radial line used as a reference for numbering base pins or contacts 3.2 General rules for base drawings 3.2.1 Wherever the bottom view of
39、the base is used, the pins or contacts shall be numbered according to Sub-clause3.3. A note should be given stating that the drawing shows the numbering of the pins as seen from their free ends. 3.2.2 Where applicable, each base drawing shall specify the maximum height of solder to be added to the o
40、ver-all base dimension for finished tubes and valves. 3.2.3 Tolerances for base dimensions depend on the possible application of the base. Normally it is recommended that the dimensions are shown as follows: 3.2.3.1 Pin diameter: plus and minus tolerance. 3.2.3.2 Length of the straight portion of th
41、e pin contact: minimum dimension. 3.2.3.3 Overall pin length: maximum dimension. 3.2.3.4 Pin positions: nominal dimensions. 3.2.3.5 Shell or wafer height: nominal dimension. 3.2.3.6 Shell or wafer diameter: maximum and minimum dimensions. 3.2.4 Base dimensions without tolerance or other limitations
42、shall be interpreted as “nominal dimensions”. Variations on such dimensions shall be consistent with current practice. 3.3 Numbering of base pins and contacts 3.3.1 Numbers shall be used to identify pins. Pin positions shall be numbered in succession in a clock-wise direction from the datum line (se
43、e Sub-clause3.3.4) beginning with the first pin position, the centre of which is past the datum line, as viewed from the free end of the pins. Each pin shall be identified by the number of its position. When a contact pin is located in the centre of the base, this may either be numbered or designate
44、d as the centre pin. If numbered, it should be the highest numbered pin. When there is a short or index pin, that pin shall not be counted in the numbering of pins.BS448-1:1981 BSI 05-2000 3 When a base has concentric pin circles of decreasing diameters, the pin positions on the pin circles shall be
45、 numbered sequentially, continuing from the highest numbered pin position in the outer circle, always numbering in a clockwise direction along a decreasing spiral. The datum line is the reference for the outer pin circle only. 3.3.2 For tubes and valves in which the leads emerge from the base in an
46、essentially linear array, the lead nearest the reference mark shall be numbered as No. 1. The other leads shall be numbered progressively from lead No. 1, but when a lead is omitted its position shall be included in the numbering of the other leads. 3.3.3 When tubes and valves have more than one bas
47、e mounted on the same bulb section, the pin numbers will be established separately for each base. 3.3.4 Methods for locating the datum line are listed below in order of preference. 3.3.4.1 The radial line through the centre of the key, the keyway or indexing boss. 3.3.4.2 The radial line midway betw
48、een the two pins most widely spaced in an otherwise equally spaced circular pin array. 3.3.4.3 The radial line midway between: the two large contact pins, or the two small contact pins. 3.3.4.4 The radial line180 from the locating radial line through the most isolated pin. 3.3.4.5 The radial line180
49、 from the locating radial line through the bayonet pin. 3.3.4.6 The radial line180 from the midway point of: the two most closely spaced pins, or the two most widely spaced pins. Where none of the above methods can be employed exactly, the method best suited for the base should be determined and used. When an unambiguous datum line cannot be established, such as in the case of a two pin base, and pin numbers are necessary, a reference mark may be used. 3.4 General rules for gauge drawings 3.4.1 A separate drawing of the base gauge should be provided to govern the spacing
