Let-Off Motion
Fig. 1.—Individual Take-Up Motion for Wide Space Looms
Fig. 2.—Individual Rubber Warp Let-Off Motion
When we remember that the front reed will pass by the rubber threads possibly six or seven hundred times from their entrance into the shed to their reaching the leaving line, it is not to be wondered at that chafing is liable to take place. With all this liability of spoiling goods it becomes readily apparent that any device employed to regulate such an important feature as the tension of the rubber warps must be very sensitive and dependable.
On looms making wide goods, and where space will allow, regulation is accomplished by a worm and gear movement as shown in Fig. 2. The iron rubber beam is threaded on to a square shaft A, at one end of which a gear wheel B is fastened. In this gear is meshed the worm C, which is operated by a heavy linen cord D passed twice around a pulley E. The cord derives its movement from a rocking shaft F, on which there is fastened a screw extension G, by which adjustment can be made so as to deliver very accurately any amount from the rubber beam.
With this kind of movement, and in order to feed the thread uniformly into the web, it becomes necessary to use mechanically made warps where the same uniformity has been maintained in putting the warps on the beams. The warps so made must come from the thread manufacturer in individual warps, which are done up in chain form, each warp containing the requisite number of threads.