Definition of Brake:
A brake is a mechanical device which is used either to stop the machine or retard the motion of a moving system. Actually the brake offers frictional resistance to the moving body and this frictional resistance retards the motion and the body comes to rest. In this process brake absorbs kinetic energy of moving member and the brake absorbs potential energy of lowering member. The energy absorbed by brakes is released to surrounding in form of heat there are two main functions of brakes: (i) To slow down or stop the machine in the shortest possible time at the time of need, (ii) To control the speed of machine so that the material will not move further.
Heat dissipation is a serious problem in brake applications. Brakes are extensively used in textile production.
Types of Brakes:
The brakes are classifies as follows:
- Hydraulic brakes
- Electric brakes
- Mechanical brakes
In textile applications, mechanical brakes are commonly used. The important mechanical brakes are as follows:
- Simple block or shoe brake
- Band brake
- Band and block brake
- Internal expanding shoe brake
What is Loom Brake?
In weaving process, loom is the principle machine that turns yarn into fabric. For smooth production of fabric, every part of the loom plays an important role. Among these, the loom brake is a very important device. Loom brake helps to stop the loom immediately whenever required. The weaver uses it to stop the loom to repair broken ends and picks.
There are various types of brake to stop a weaving machine: electromagnetic, frictional shoe, disk or cone. Older designs of brakes were based on a spring-operated single brake shoe which pressed onto a brake pulley externally. In order to increase the capacity of the brake, later designs employ two brake shoes, which are contained within the brake pulley.
Loom Brake Mechanism in Weaving Machine
The principle of operating loom brakes is very similar in a wide range of looms. The movement of the starting handle from the ON to the OFF position causes a brake band to close round the flat perimeter of a wheel (Figure 1) which is mounted on the main shaft of the loom and is acting as a brake drum. Such a system is likely to vary in efficiency, depending upon the angle of lap over which the brake band makes contact with the brake drum, the coefficient of friction, and the condition of the two surfaces. The presence of foreign matter, such as oil on the surface is quite detrimental to efficient braking. It is preferable that the braking system should allow the loom to be brought to rest at the desired position in order to allow a yarn break to be repaired without intermediate manual or mechanical adjustment of the loom position. Examples of this requirement are:
- With the healds level if the warp stop-motion stops the loom for an end-break.
- With the sley around the back-centre position on the pick after a weft break has been detected by the side-weft fork motion; and
- Before beat-up on the actual pick of the weft break if the centre weftfork motion is responsible for stopping the loom in weaving a fabric in which pick-finding is almost certain to create a setting on place.
The braking system in the last of these instances needs to be highly efficient and, for this reason, brake drums on looms having centre weft forks usually have larger angles of lap, the brake band having a high coefficient of friction and covering almost the whole of the perimeter of the brake drum in order to spread the weaver over a greater area and dissipate the heat created.
Loom Brake System
A brake is a device by means of which artificial frictional resistance is applied to moving body in order to stop the motion of a loom (Figure 2).
The assumption that the loom will always come to rest in the required position is quite unrealistic, and frequently it is necessary to adjust the position of the stopped loom manually by releasing the brake and turning the hand-wheel of the loom. Alternatively, the starting handles maybe drawn towards the ON position and released as soon as the sley has moved forward to the required position. A small movement of the sley (inching) is generally achieved with each pull of the starting handle, but it is tricky manoeuvre, which lacks accuracy. Mechanical reversing of the loom from the top and front centre positions becomes desirable after the redrawing of a broken end or the detection of a weft break. It saves time and effort on the part of the weaver.
Importance of Loom Brake in Weaving
Without a proper brake system, weaving machines cannot produce quality fabric. If the loom doesn’t stop at the right time:
- Warp tension will be disturbed.
- Broken ends will increase.
- Fabric defects and wastage will rise.
- Loom safety will be at risk.
Thus, the loom brake ensures safety, quality, and efficiency in textile production.
Conclusion
Loom brake may look like a small part of the weaving machine, but it plays a big role in controlling production. From handlooms to modern air-jet looms, every type of weaving machine depends on brakes for smooth operation.
References
[1] Hayavadana. (2018). Textile Mechanics and Calculations. Woodhead Publishing India in Textile.
[2] Gorkaneshan, N., Varadarajan, B., & Kumar, C. B. S. (2012). Mechanics and calculations of textile machinery. WPI Publishing.
[3] Nagarajan, G. (2025). Textile mechanisms in spinning and weaving machines.
[4] Choogin, V. V., Bandara, P., & Chepelyuk, E. V. (2013). Mechanisms of flat weaving technology. Woodhead Publishing.
[5] Adanur, S. (2020). Handbook of Weaving. CRC Press.
Founder & Editor of Textile Learner. He is a Textile Consultant, Blogger & Entrepreneur. Mr. Kiron is working as a textile consultant in several local and international companies. He is also a contributor of Wikipedia.
