Feed Mechansim by Friction Disc
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Feed Mechansim by Friction Disc
Feed Mechansim by Friction Disc - Fig. shows different parts of a planer and the feed mechanism by friction disc. Friction disc 'a' is fed from the drive mechanism of the planer table. As the planer table reciprocates, the friction disc rotates through a part of the revolution in one direction at the beginning of cutting stroke and as a in it rotates through the same part of the revolution in tbe opposite direction at the beginning of return stroke.
| A - Table | G - Saddle | M - Fied Gears | S & T - Stroke Dogs |
| B - Tool Post | H - Ways | N - Par | U - Bed |
| C - Hinge | I - Bevel Cears For Crossrail vertical Adjustment | O - Feed screw gear | V - Reverse Lever |
| D - Head | J - Housings | P - Drive Shaft | |
| E - Vertical Feed | K - Crossrail | Q - Leg | |
| F - Slide | L - Pawl | R - Feed Adjustment Mechanism |
| A - Crossrail | F - Clapper | K - V Ways | P - Stroke Dog |
| B - Vertical Feed | G - Swivel | L - Housing | Q - Feed Gears |
| C - Slide | H - Table | M - Legs | R - Feed screw Gear |
| D - Head | I - Feed Screw | N - Bed | S - Pawl |
| E - Saddle | J - Table Rack | O - Feed Mechanism | T - Rack |
Feed Mechanism of a Planer
The motion from the disc is transferred to the rack with the help of a block 'b' and connecting rod ‘d'. The position of block 'b' can be brought towards or away from the center of the disc with the help of handle 'c'. The position of block 'b' will decide the magnitude of movement of rack and hence the amount of feed.
The upward movement of the rack rotates the feed gears (Fig.) which in turn rotate the feed screw gear, The direction of rotation of feed screw gear can be controlled by the pawl. In (Fig.), the left hand end of the pawl is within the teeth of feed screw gear, thus the upward movement of the rack will rotate the feed screw gear in the clockwise direction.
The feed screw gear will rotate the feed screw (Fig.) and hence the tool head will move at right angle to the direction of motion of the worktable or workpiece,
When the friction disc or feed disc will start revolving in the direction opposite to that explained above, the rack will move downward, and the feed gears will rotate in anticlockwise direction.
The edge of the pawl, because of its position, will just slip over the teeth of feed screw gear and no motion will be transferred to feed 'screw. Thus, the feed screw will rotate and move the tool head in one direction only during a double stroke of the work table and that too at the beginning of cutting stroke only. The direction of movement of toolhead can be reversed by pushing the right hand end of the pawl within the feed screw gear.
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