Question

In which of the following machine tool; 'clapper box' in which the cutting tool is clamped, is used:

• A. Lathe
• B. Drilling Machine
• C. Shaping Machine
• D. Milling Machine

Hint:

To remember this, think of the Shaper. It goes back and forth like a Swing. Just like a door Claps shut, the Clapper box on a Shaper flaps up and down during its return stroke.

Answer 1

The Correct Option is C

1. Function of the Clapper Box: The

clapper box is a critical component of the tool head in a

Shaping Machine. It is a hinged unit that holds the tool post.

• Forward (Cutting) Stroke: The clapper box is held firmly against the vertical slide by the force of the cut, ensuring the tool remains rigid as it removes metal.

• Return (Idle) Stroke: On the way back, the hinge allows the tool to lift slightly and "clap" or drag lightly over the surface. This prevents the sharp edge of the tool from rubbing against the freshly machined surface, which would cause excessive tool wear and ruin the surface finish.

2. Analyzing the Shaper Mechanism: In a shaper, the tool moves while the workpiece remains stationary (except for the cross-feed). Because the stroke is horizontal and reciprocating, the automatic lifting action of the clapper box is necessary to avoid friction during the idle return stroke.

3. Comparison with Other Tools:

• Lathe: Uses a continuous cutting action where the tool is constantly in contact with the rotating workpiece.

• Milling Machine: Uses a rotating multi-point cutter.

• Drilling Machine: Uses a rotating drill bit that moves axially.
None of these machines have a "return stroke" where the tool needs to be lifted away from the surface, so they do not require a clapper box.