Jigs and Fixtures
In modern engineering, there is no application of jigs in mass production. It is like looking for needle in a haystack. During the past ten decades, many changes have been witnessed in the sphere of production engineering. Teachers have become more adventurous in their approach to the work by giving their students the opportunity of constructing such exciting engineering, casting and foundry work enamellings and etchings in metal work to an extent that would have been thought impossible to achieve years ago. It is considered now that the most important aspect of education through craft is that the work should be developed along creative lines so that the students are able to solve problems of design construction by themselves.
Jigs are designed to ease certain difficulties in craft operations; they are flexible enough in use to be adapted in a variety of ways to suit the production and are not a substitute for skills. However, some experts in the field of engineering production disapprove the use of jigs with a view that the use of jigs underlines the skills of the production engineer. It is seen as a substitute for skill and means of institutionalizing laziness on the part of engineers. Such experts conclude that the uses of jigs are unprofessional. However, in spite of that sound argument, it is still interesting to learn of the decision of a vast majority of production engineers who believe that the use of jigs enhances production and does not in any way replace skills which are normally taught in schools. Jigs wide the scope of operation and reduce the difficulty of operational skill and also allow for flexibility and adaptability in various ways. The design of jigs and fixtures gives a selection of jigs found in current usage in the British industry.
Some of the designs cover non-standard and commercially available standard units with an emphasis on various clamping techniques employed. There are different types of drilling jigs and the principal ones are:
- Simple built-up jigs;
- Local jigs with angular base;
- Jigs milled from solid;
- Jigs for multi-drill;
- Turning jigs;
- Indexing jigs;
- Air-operated jigs;
- Box-type jigs;
- Latch-jigs;
- Pot-type jigs;
- Arrangements to assist in the handling of the work piece.