Group I Group II P Conjugate/matched cams 1 Driving the cloth roller with slip
driveQ Worm and worm wheel 2 Continuous positive take up
motionR Friction clutch device 3 Motion of sley in rapier loom S Lease rod 4 Separation of the warp sheet
forming the shed
Weaving Machine Components and Functions Explained
This question involves matching specific components of a weaving machine, listed in Group I, with their corresponding functions found in Group II. Understanding these parts is crucial for comprehending how a loom operates.
Group I: Components
- P: Conjugate/matched cams
- Q: Worm and worm wheel
- R: Friction clutch device
- S: Lease rod
Group II: Functions
- 1: Driving the cloth roller with slip drive
- 2: Continuous positive take-up motion
- 3: Motion of sley in rapier loom
- 4: Separation of the warp sheet forming the shed
Detailed Matching and Explanation
Component P: Conjugate/matched cams
Function Match: 3 - Motion of sley in rapier loom
Conjugate or matched cams are specialized mechanical components used to create precise motion profiles. In certain types of looms, like rapier looms, they are instrumental in controlling the back-and-forth movement (reciprocation) of the sley. The sley holds the reed, which is responsible for 'beating' the weft yarn into place after it's inserted.
Component Q: Worm and worm wheel
Function Match: 2 - Continuous positive take-up motion
The worm and worm wheel is a gear mechanism known for providing a smooth, continuous, and positive drive, often with a significant speed reduction. In weaving, this mechanism is typically used for the cloth take-up system. It ensures that the woven cloth is rolled onto the cloth roller at a constant and controlled rate, which is vital for maintaining uniform fabric density.
Component R: Friction clutch device
Function Match: 1 - Driving the cloth roller with slip drive
A friction clutch is a device used to connect or disconnect a driving power source from a driven load. In the context of driving a cloth roller, a friction clutch can be configured to provide a 'slip drive'. This allows the roller to rotate slightly if excessive tension builds up, acting as a protective measure for the warp yarns and the fabric being produced.
Component S: Lease rod
Function Match: 4 - Separation of the warp sheet forming the shed
Lease rods are flat bars or rods used early in the weaving process. Their primary function is to maintain the precise separation of the warp yarns, creating distinct layers or 'sheets'. This orderly separation is essential for the subsequent operation of the healds and harness, which lift and lower specific warp threads to form the 'shed' – the opening through which the weft is passed.
Summary of Correct Matches
The correct pairings between the weaving machine components and their functions are as follows:
| Component (Group I) | Function (Group II) | Reasoning |
|---|---|---|
| P: Conjugate/matched cams | 3: Motion of sley in rapier loom | Cams dictate the specific movement pattern of the sley in certain looms. |
| Q: Worm and worm wheel | 2: Continuous positive take-up motion | This gearset ensures smooth, consistent winding of the cloth. |
| R: Friction clutch device | 1: Driving the cloth roller with slip drive | Used for controlled tension and smooth engagement in cloth rolling. |
| S: Lease rod | 4: Separation of the warp sheet forming the shed | Essential for keeping warp threads organised for shedding. |
This detailed breakdown confirms the correct set of matches.
Important Questions from FABR Loom Mechanisms Shedding
Amongst the following, the correct condition(s) that will reduce bumping during weaving is/are
- Group I lists weaving machine related parameters and Group II contains the shortcomings of these parameters. Match the machine related parameter with its shortcoming.
Group I Group II P. Variable heald staggering 1. Not favourable for heavy fabric Q. High eccentricity ratio 2. Reduction in shed height R. Fixed heald staggering 3. Reduction of sley dwell S. Late shedding 4. Higher vibration in weaving machine Group I gives a list of loom motions and Group II contains loom systems. Match the motion from Group I with the corresponding system from Group II.
Group I Group II P. Shedding 1. Matched cam Q. Picking 2. Seven wheel R. Beat-up 3. Rapier S. Take-up 4.Jacquard Determine the correctness or otherwise of the following Assertion [a] and Reason [r]
Assertion: In shuttle loom, late shedding is preferred for filament weaving.
Reason: In late shedding, the timing of shed dwell matches with the timing of shuttle travel through the shed, and therefore, it minimises the rubbing of warp yarns.
For a shuttle loom, producing plain woven fabric, if each of the dwell periods of the shedding cam corresponds to one-third of crank shaft rotation, the sum of the two dwell periods of the cam (in degree) is_____.
