Slotter
Slotter is a type of reciprocating machine. The tool is held in the ram
reciprocates vertically and the work piece is held on the table. The
slotter has a base upon which the column is being integrated. The column
houses the driving mechanism for the ram. The top portion of the ram
has the guide ways. With the help of this guide ways the ram
reciprocates vertically. This reciprocation is achieved by the quick
return mechanism. The base has horizontal guide ways which enables the
saddle to move perpendicular to the column.
The top face of the saddle has guide ways. These guide ways are
perpendicular to the guide ways present in the base over which a cross
slide moves. This movement is parallel to the column face.
A circular shaped rotary table is mounted on top of the cross slide.
This rotary table can be rotated about a vertical axis parallel to the
column. This movement is the circular feed for the table. All the
feeding systems are graduated.
T- Slots are
being provided on the table for holding the work piece. The
longitudinal feed of the saddle, the cross feed of the cross slide and
the rotary movement of the table in all these feeding mechanism the feed
can either be given by hand or by power.
Quick return mechanism
Metal from the work piece is removed only during the cutting stroke.
During the return stroke no metal is being removed. To reduce the idle
time of the return stroke quick return mechanisms are being used. The
following are the generally used quick return mechanisms in a slotting
machine.
· Whitworth quick return mechanism.
· Variable speed reversible electric motor drive.
· Hydraulic drive.
Feed mechanisms
The following are the feed mechanisms generally used in a slotter
· Longitudinal feed: This movement is achieved by moving the saddle either towards or away from the column.
· Cross feed: This is obtained by moving the cross slide parallel to the face of the column.
· Circular feed: This is obtained by rotating the table about a vertical axis.
Automatic feed
A groove for the cam is cut on the face of the bull gear of the driving
mechanism of the slotter. A roller follower slides in this groove. The
roller is fixed at one end of the lever. The lever is pivoted in the
middle and the other end of the lever has a slot. In this slot a feed
adjustment pin is fitted.
This pin is connected by a connecting rod to the pawl and ratchet mechanism.
The bull gear starts to rotate, the follower follows the groove
profile. When the lobe portion of the cam groove passes the follower,
the slotted end of the lever moves up and down. This makes the pawl to
rotate the ratchet wheel. The ratchet is keyed to the feed shaft. This
feed shaft is engaged with the longitudinal, cross or rotary feed
screws. This makes to achieve automatic feed.
The amount of feed can adjusted by shifting the location of the feed adjustment pin in the lever slot.
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