Having studied about basics of a turret lathe and the various types of turret lathes, it is now time to take a look at the various attachments which are used on turret lathes to carry out a wide variety of operations that add to the versatility of the machine. Though the exact number of attachments used in such lathes is quite large, I will limit myself to tell you about a few of the most commonly used attachments which solve the various purposes for which these machines are used.
As you know a turret lathe is used to manufacture similar parts in large numbers, hence if the parts being manufactured are from a bar which is being fed through a spindle, there must be an arrangement to ensure that the work pieces produced are similar to each other in size. One way of ensuring this is use the turret with a stopper in position so as to act as locator for the bar end, which adjusts the length of the bar projecting out of the spindle by locating the end of the bar against the stopper. In this way the operator can be sure that the dimensions of the parts produced in such a manner are as close to each other as practically possible provided any other factors regarding the same are also kept in mind.
Roller Box Attachment
If you take a close look at the adjacent diagram, you will understand what a roller box arrangement looks like. The four parts shown in the sketch consist of two rollers, the work-piece and the cutting tool which are not labeled on the diagram itself but can be easily singled out.
You can easily imagine that when the cutting tool is performing its operation, the rollers perform the function of maintaining concentricity on the work as well as to prevent deflection of the work piece and the end result is a much smoother finish, than what could be obtained using the cutting tool alone.
Screw Cutting Die Heads
Sometimes it may be required to cut threads in the work piece but not along its entire length. In such a case it very convenient to use a self opening die head which comes in various shapes and sizes to be fitted onto the turret lathe. After the set portion of the job piece has been threaded, the die automatically opens up thus clearing the thread portion of the work piece and returns back with the turret head.
Another similar attachment is the collapsing tap which is used to cut internal threads on the work piece and uses a similar principle of working to ensure that threads are cut only as required.
Knee Turning Tool
This type of attachment is used to perform the operations of boring and turning simultaneously especially for work pieces which have a relatively large diameter. The pictorial representation of this type of arrangement is shown in the adjoining diagram which shows a clearly labeled sketch of the same and is fairly self-descriptive.
There are several other types of attachments and we will learn more about them in a later article.
Production Technology by Jain & Gupta. New Delhi: Khanna Publishers