Main parts of Turret Lathes

Main parts of Turret Lathes

Main parts of Turret Lathes - The main parts of a horizontal turret lathe are:

(i) Bed

(ii) Head stock, spindle, chuck etc.,

(iii) Carriage

(iv) Turret.

(v) Bed

The bed is a long, box like casting fitted with rectangular ways upon which are mounted the carriage, and turret. It also supports the headstock. The bed provides strength and rigidity to other parts. It ensures proper alignment of parts also.

(ii) Headstock The headstock is a large casting located on the left end of the bed. It houses the transmission mechanism (gears etc.) which operates the spindle at various speeds. These speeds are controlled by the built in speed selector.

A modern turret lathe uses either an electric head with a multiple speed motor mounted directly on the spindle or an all geared head is used.The operator needs only to set the dial to the diameter of work, and the spindle speed selector will automatically shift to the correct speed.

(iii) Carriage: The carriage is fitted over the ways of the bed. Mounted on it is the tool post. The front of the carriage includes the apron which contains the feed mechanism.

The carriage has reversible power longitudinal feeds ranging from 0'125 to 4'5 mm and also reversible power cross feeds ranging from 0'050 to 2'25 mm per revolution of the spindle.Most models have longitudinal and cross-feed positive stops which act to disengage the feed according to the specification the work.

(iv)Turret :The turret is a hexagon on square shaped tool holder mounted on the saddle or carriage on the bed ways. The main ram turret usually is six sided, and provision is made for mounting tools on each of the six faces. The turret can be rotated about a vertical axis to bring each tool into operating position, and the entire unit can be moved longitudinally, either manually or by power, to provide feed for the tools.

The cross slide turret also can be rotated manually about a vertical axis to bring each of the four tools into operating position. On most machines the turret can be moved transversely, either manually or by power, by means of the cross slide and longitudinally through power or manual operation of the carriage.

In most cases, a rear tool post also is added to the back end of the cross slide; this often carries a parting tool. The tools held in the turret may be used to perform certain operations on a workpiece, while at the same time, other tools held in the square tool post mounted on the carriage do other operations.

The workpiece having been previously chucked correctly, with these basic features of a turret lathe, a number of tools can be set up on the machine and then quickly be brought successively into working position so that a complete part can be machined without the necessity for further adjustment or changing tools or making measurements.

Operations such as roughing, knifing, tapping, boring etc., can be performed merely by rotating the hexagon turret and presenting to the workpiece a different tool secured in the turret, in order of sequence.