IS/ISO 9962 : PART 3 : 1994 Manually Operated Draughting Machines - Part 3 : Dimensions of Scale Rule Chuck Plates

NATIONAL FOREWORD

This Indian Standard which is identical with ISO 9962-3 : 1994 ‘Manually operated draughting machines - Part 3 : Dimensions of scale rule chuck plates’, issued by International Organization for Standardization ( ISO ) was adopted by the Bureau of Indian Standards on the recommendation of the Optical and Mathematical Instruments Sectional Committee ( LM 20 ) and approval of Light Mechanical Engineering Division Council.

The standard has been published in following three parts:

Part 1 Definitions, classification and designation;

Part 2 Characteristics, performance, inspection and marking: and

Part 3 Dimensions of scale rule chuck plates.

The requirements of draughting machines were earlier covered in IS 2287 : 1970 ‘Specification for drafting machines,4 first revision )’ which will be withdrawn after publication of all three parts. IS 2287 : 1970 was also covering the certification of draughting machines which will now be covered by Part 2 of IS/ISO 9962-2 : 1992.

In this standard, the straight slots have been provided for scale rule chuck plates as shown in Fig. 1 b and Fig. 2b. The Indian industry, however, is mostly manufacturing and using scale rule chuck plates having radial slots. Therefore, provisions for radial slot have also been included as an alternate to straight slot and are given in National Annex of the standard.

The standard covers 60 mm and 63 mm pitch of holes ( see Table 1 ) in respect of large scale rule chuck plates, though only 60 mm pitch of holes is commonly used.

The text of ISO Standard has been approved as suitable for publication as Indian Standard without deviations. Certain conventions are, however, not identical to those used in Indian Standards. Attention is particularly drawn to the following:

a) Wherever the words’International Standard’appear referring to this standard, they should be read as ‘Indian Standard’.

b) Comma (,) has been used as a decimal marker while in Indian Standards the current practice is to use a point (.) as the decimal marker.