Types of Slotters, Types of Drives and Main Parts of Slotting Machine

Types of Slotters

Various types of slitters are designed to suit various requirements. There are three types of slotters.

(a) Puncher Slotter - The puncher slotter is a heavy, rigid machine designed for removal of large amount of metal from large forgings or castings. The length of stroke of a puncher slotter is sufficiently large. It can remove 1.5 Kg to 2.5 Kg of material in one minute. Locomotive crank webs can be slotted from the rectangular shapes to exact size in less time than by any other method.

(b) General Production Slotter - This is widely used for general purpose production work. This may be divided into two classes. These are as follows:

(i) Those having solid body construction

(ii) Those having arrangements to tilt the body of the machine about 10^O forward and backward for machining accurate internal and external tapers.

(c) Precision Tool Room Slotter - A considerable amount of tool room work is carried out on standard production slotter but the value of a precision slotter for this class of work cannot be over estimated as importance of accuracy in most cases, is of paramount importance. The slotter frame may be of tilting type with slotted link type of ram drive. The slotter operates at high speeds and is designed to take light cuts to produce accurate finish. In the larger machines, all the table and hand control are conveniently grouped together so as to perform profiling operation, where two feeds are to be used simultaneously.

Types of Drives

These machines utilize three types of drives. These are rack driven, screw driven, and crank driven. The crank drove being most common because of the variety of work; which they undertake, normally.

Main Parts of Slotting Machine

The various main parts of slotting machine are as mentioned below:

(a) Frame or Column - This is a massive casting of great strength designed to carry all the working part of the machine.

(b) Table - Table of slotter holds the work piece and is adjustable in longitudinal and cross-wise directions. The table can be rotated about its centre. Hand wheels are provided for longitudinal, cross and rotary movements of the table.

Note:    The transverse and longitudinal movements are at 90^O to each other.

(c) Carriage - This carries the table to which it is mounted and provides means for transverse movement of the table.

(d) Saddle - This is mounted on the carriage, which carries the table and provides means for longitudinal movement of the table towards or away from the column.

(e) Bed Ways - These carry the saddle and provides guide for the longitudinal movements of the saddle.

(f) Ram - This part carries the cutting tool. It is similar to the ram of shaper but more massive and moves vertically or at a right angle to the table instead of having the horizontal motion of the shaper.

(g) Ram Guides - These restrict the ram to its path of motion.

(h) Counter Weight - The ram of the Slotting Machine is a hanging part. The counter weight acts as a balancing weight for the ram during the operation and prevents jerky action of the ram.

(i) Cone Pulley - This is the driving pulley to which power is applied from an external source to drive the slotter. The steps provide a different speed of driving.

(j) Drive Pinion - This is keyed to the cone pulley shaft and meshes with large bull gear.

(k) Bull Gear - This gear is much larger than the drive pinion and gives the necessary relative speed reduction between the cone pulley and crank disc.

(l) Crank Disc - The disc is keyed to the bull gear shaft and revolves with it.

(m) Crank - The crank is movably mounted in a radial slot in the crank disc to which it can be rigidly clamped.

(n) Stroke Adjustment Screw - By turning screw one way or the other, it may be moved towards or away from the crank disc, centre, thus shortening or lengthening the ram stroke.

(o) Connecting Rod - This link connects the ram and crank and changes the rotary motion of the crank into the reciprocating motion.