Various types of jigs used are described below:
Type # 1. Template Jigs:
They are the simplest type used more for accuracy than speed. This type of jig fits over, on, or into the work and is not usually clamped, (Refer Fig. 28.15). If bushings are not used, then the whole jig plate is normally hardened.
Type # 2. Plate Jigs:
They are similar to templates excepting that these have built-in clamps to hold the work. (Refer Fig. 28.16).
Type # 3. Table Jig:
This is similar to plate jig except that legs are provided to raise the jig off the table for large work.
Type # 4. Sandwich Jig:
This type of jig is used for drilling thin or soft parts to avoid bending, warping etc. For this purpose a support plate is provided at bottom and top jig is located by use of locating pins. (Refer Fig. 28.17).
Type # 5. Angle-Plate Jigs:
These are used to hold parts which are to be drilled at right angles or some other angles to their mounting locators.
Type # 6. Box Jigs:
These jigs usually totally surround the part. Since the part is completely located and held within the box, it is possible to drill holes from all the sides.
Type # 7. Channel Jig:
It is the simplest form of box jig. The jig is placed over the work and is located by one side of work and clamped from other side. (Refer Fig. 28.19).
Type # 8. Leaf Jigs:
These are small box type jigs with a hinged leaf to permit easy loading and unloading of part. (Refer Fig. 28.20). Normally, these do not completely surround the part.
Type # 9. Indexing Jigs:
These are used to accurately space holes or other machined areas around a pant. Indexing is achieved by using a reference plate and a plunger. (Refer Fig. 28.21).
Type # 10. Trunion Jigs:
These are used for drilling holes on very large or odd-shaped parts from different sides. The part is first put into a box-type carrier and then loaded on the trunion.
Type # 11. Multi-Station Jig:
On this jig, several operations can go on simultaneously. While one part is drilled, another can be reamed and a third counter-bored. The final station may be used for unloading the finished parts and loading fresh parts. This jig is commonly used on multiple-spindle machines.