Introduction to Basic Manufacturing Processes and ... - always yours

442 Introduction to Basic Manufacturing Processes and Workshop Technology
Machining splines and cutting gears
Index plate
Worm gear
23.9 PLANER
Index
pin
Worm handle
C ylindrical
job
Tail stock
Fig. 23.13 Machining splines and cutting gears on shaper
Like a shaper, planer is used primarily to produce horizontal, vertical or inclined flat
surfaces by a single point cutting tool. But it is used for machining large and heavy workpieces
that cannot be accommodated on the table of a shaper. In addition to machining large
work, the planer is frequently used to machine multiple small parts held in line on the platen.
Planer is mainly of two kinds namely open housing planer and double housing planer. The
principle parts of the open housing planer are shown in Fig 23.14(a). The principle parts of
the double housing planer are shown in Fig 23.14(b). The bigger job is fixed with help of the
grooves on the base of the planer and is accurately guided as it travels back and forth. Cutting
tools are held in tool heads of double housing planer and the work piece is clamped onto the
worktable as shown in Fig. 23.14(b). The worktable rides on the gin tool heads that can travel
Tool head
Cross rail
Cross - rail
Column
Tool
heads
Colum n
Table
Work
piece
Bed
(a) Open Side Planer
Base
(b) Double Housing Planer
Work-table
Fig. 23.14 Principle parts of double housing planer
from side to side i.e., in a direction at right angle to the direction of motion of the worktable.
Tool heads are mounted on a horizontal cross rail that can be moved up and down. Cutting
is achieved by applying the linear primary motion to the workpiece (motion X) and feeding
the tool at right angles to this motion (motion Y and Z). The primary motion of the worktable
is normally accomplished by a rack and pinion drive using a variable speed motor. As with
the shaper, the tool posts are mounted on clapper boxes to prevent interference between the
tools and work-piece on the return stroke and the feed motion is intermittent. The size of