Question

Consider the following statements with regard to the timing diagram of a cotton combing machine.
P. In forward feed system, feeding mostly takes place when nippers are closing
Q. Cylinder comb starts combing after feeding ends
R. Detaching rollers move backward during forward movement of nipper assembly
S. Top comb is not combing when detaching rollers move forward
The correct combination of TRUE statements is:

• A. P and Q
• B. Q and R
• C. R and S
• D. S and P

Hint:

Always match each statement with the mechanical sequence of the combing machine. Inference questions often test whether you recall the exact synchronization between feeding, combing, and detaching actions.

Answer 1

The Correct Option is B

Let us carefully analyze each statement based on the timing diagram of a cotton combing machine:
Step 1: Analyze P
P says that in the forward feed system, feeding mostly takes place when nippers are closing. This is not true. In the forward feed system, feeding takes place when nippers are open, not closing. Hence, statement P is false.
Step 2: Analyze Q
Q says that the cylinder comb starts combing after feeding ends. This is correct because the cylinder combing action begins only once the feeding of fibers into the nip is completed. Hence, statement Q is true.
Step 3: Analyze R
R says that detaching rollers move backward during forward movement of the nipper assembly. This is true because during the forward stroke of the nippers, the detaching rollers must move backward to maintain synchronization of the fibers and prevent disturbance of the sliver formation. Hence, statement R is true.
Step 4: Analyze S
S says that the top comb is not combing when detaching rollers move forward. This is false, because the top comb continues its combing action during the forward motion of detaching rollers in order to remove short fibers effectively.
Step 5: Conclusion
From the analysis:
- P is false
- Q is true
- R is true
- S is false
Thus, the correct combination of true statements is \fbox{Q and R}.