Skip to main content
UploadLanguage (EN)Support
BusinessMobileSocial MediaMarketingTechnologyArt & PhotosCareerDesignEducationPresentations & Public SpeakingGovernment & NonprofitHealthcareInternetLawLeadership & ManagementAutomotiveEngineeringSoftwareRecruiting & HRRetailSalesServicesScienceSmall Business & EntrepreneurshipFoodEnvironmentEconomy & FinanceData & AnalyticsInvestor RelationsSportsSpiritualNews & PoliticsTravelSelf ImprovementReal EstateEntertainment & HumorHealth & MedicineDevices & HardwareLifestyle
Shad Ibna Shoiel, profile picture
Uploaded byShad Ibna Shoiel
PPTX, PDF12,779 views

Take up mechanism

The document discusses take-up mechanisms in weaving. It describes take-up motion as the process of withdrawing woven fabric from the weaving zone and winding it onto the cloth roller. There are two main types of take-up motions - positive and negative. Positive take-up directly drives the cloth roller via gear trains, while negative take-up uses a system of levers and weights to indirectly drive the roller. Specific take-up mechanisms like five-wheel and seven-wheel are also described, including their components and working principles. The document provides an overview of different take-up motions used in weaving to uniformly wind the fabric.

Education◦
Downloaded 255 times
TOPIC Take-up Mechanism
WEAVING Weaving is the process of interlacement between the warp and the weft in a fabric according to design.
Take-up is to draw a fabric to the cloth roller regularly as it is woven. Texture of a fabric largely depends upon the number of ends and picks per centimeter or inch. This motion determines the number of picks of weft per inch or centimeter and contributes to the uniform texture of the fabric. It is the work of the weaver for accurately fixing the position of the fell of the cloth before starting a loom. Take up
TAKE UP MOTION The process of withdrawing fabric from weaving zone at a constant rate and then winding the woven cloth on the cloth roller with the continuous progress of weaving is called take up motion
Objective of Take-up Motion To wind the woven fabric on the cloth roller with progress of weaving. To maintain uniform picks per inch. To know about the construction of the mechanism. To know about drive of the take-up motion.
Types of motions According to drive: Positive take up Negative take up According to motion of the cloth/Rate of take up: Continuous Intermitten According to drive given to the cloth roller:  Direct drive  Indirect drive According to number of gear train: 5-Wheel 6-Wheel 7-Wheel According to brand name: Sulzer Pickanol Toyota
Main parts& Specifications Sley Sleysword Connecting rod Monkey tail Holding/Catching/Locking pawl. Pulling pawl Rachet Wheel(24) Standard wheel(36). 9.Changewheel(1-Let) Sewing wheel/Pinion(24 Stud/Compound wheel(89) Stud/Compound Pinion(14) Take up wheel(89) Take up roller(dia:15.5 inch) Cloth rolle
Motion Transfer Sley sword to connecting rod→ Connecting rod to monkey tail→ Monkey tail to pawl→ Pawl to ratchet wheel→ Ratchet wheel to standard wheel→ Standard wheel to change wheel → Change wheel to sewing wheel→ sewing wheel to stud wheel→ Stud wheel to stud pinion→ Stud pinion to take up wheel → Take up wheel to take up
Working Principle The motion is primarily imparted from the sleysword→ The sleysword is connected to the slay that gets motion from crank shaft and the crank shaft gets motion from motor by gearing→ At the bottom of sleysword a connecting rod is connected which passes the motion to the monkey tail. The monkey tail is fulcrum with two pawls: the upper is holding pawl and lower is pulling pawl→ These two pawls are mounted freely to the ratchet wheel which is connected with the standard wheel by shaft→ Over the standard wheel the change pinion is geared→ The change pinion is connected with the stud pinion by shaft and the stud wheel is geared with the stud pinion upon it→ The swing pinion is connected with the stud wheel and the cloth take-up roller wheel is geared with the swing pinion.
The cylinder upon which the woven fabric is wound, is connected with this wheel by shaft→ Now when the sley moves one time after one pick insertion the connecting rod pass this motion to the monkey tail and as the pawls are fulcrum with monkey tail they get downward motion→ Using this downward motion the pushing pawl pulls the rachet wheel one time and the holding pawl holds the rachet in this position→ Finally the cloth roller gets the motion by gear train and thus fabric is wound on cloth roller continuously with the weaving of fabric.
Negative Take-Up Attribute ‘negative’ justifies itself in the sense that no positive or direct motion is imparted to the take-up roller to wind up the woven fabric. In this system, shown in Figure. the motion of the rocking shaft actuates a system of levers and a ratchet-pawl mechanism, favored by gravity aided movement of dead-weights which in turn, transmits the rotational motion to take-up roller through a worm and worm-wheel. Backward motion of the sley ( S) or backward swing of the rocking shaft ( R) keeps the weights raised through a lever (L1) , thus system remains inactive while forward motion of it sets free the weight system yet motion of the wheel trains remains balanced with warp tension . The impulsive blow of sley during beat-up brings the tension of the woven cloth close to zero.
Weights (W) going down with gravity forces the pawl (P1) to turn the ratchet by one tooth through lever systeams. Gear trains so released wind up the excess woven part of the cloth. Retaining pawl (P2) comes into play to prevent further rotation of gear trains. With little control over uniform take-up or pick spacing, this system is only suitable for very coarse fabric like blanket.
Positive Take-Up In positive take-up, motion gets transmitted to take-up roller directly through gear train. The different types of positive take-up are discussed below.
Five-wheel Take-up Five-wheel take-up motion is The typical size of the gear is also given in the Figure. It is a positive intermittent type take-up motion. Wheel CW denotes the change wheel which is in the driver position for five-wheel take- up. The amount of fabric take-up and therefore the rotation required in the take- up roller after every pick is minuscule. This is achieved by keeping the driver wheels smaller than the driven wheels. The ratchet wheel A, having 50 teeth, is turned by one tooth for every pick.
Seven-wheel Take-up Seven-wheel take-up is a discontinous positive motion.A swing motion is given to take-up lever and this will cause the pulling pawl to drive theratchet wheel and set the turn of motion.Thus take-up roller gets motion. Figure : Seven-wheel take-up
Working Principle Here the pulling pawl is connected to the slay which is connected to the crank shaft.When the crank shaft rotates the sley sword gets to and fro motion which causes the pulling pawl to pull the the one teeth of ratchet wheel.Then the motion is transferred to the take up roller from the ratchet wheel by means of seven wheels.
Advantages of 7 take-up wheel over 5 wheel take-up mechanism: 1. It can give a larger number of picks per inch in cloth from a small stock of wheels by changing two wheels in the train 2. It can give even a fraction of a pick per inch in cloth. 3. The number of teeth in the change wheel and the number of picks per quarter-inch has been simplified
From the presentation we know about how to cloth is collected by take up mechanism. Also we learn the different type of mechanism. I think this would be very helpful in our future career