Sufficient be it to say that the combed cotton leaves the detaching rollers in a thin silky-looking fleece which is at once gathered up into a round sliver or strand and conducted down a long guide-plate towards the end of the machine. This guide-plate is clearly shown in the photograph of the comber, where also it will be seen that the slivers from the six laps which have been operated upon simultaneously are now laid side by side.
In this form the cotton passes through the "draw-box" at the end of the comber, and being here reduced practically to the dimensions of one sliver it passes through a narrow funnel and is placed in a can in convenient form for the next process.
When the combing is adopted, it precedes the drawing frame, which has previously been described, and the cans of sliver from the comber are taken directly to the draw-frame.
For intricacy and multiplicity of parts of mechanism, the comber is second only in cotton-spinning machinery to the self-acting mule, and is probably less understood, since its use is confined to a section of the trade. The latest development is the duplex comber, which makes the extraordinarily large number of one hundred and twenty nips per minute, as compared with about eighty-five nips per minute for the modern single nip comber. All this is the result of improvement in detail, as the principle of Heilman's Comber remains the same as he left it. It ought to be added that other types of comber have been adopted on the continent with some show of success.
=Sliver Lap Machine.=--Combing succeeds carding and is practically a continuation of the carding principle to a much finer degree than is possible on the card. The Carding Engine, however, makes slivers or strands of cotton, while the comber requires the cotton to be presented to it in the form of thin sheets. It therefore becomes requisite to employ apparatus for converting a number of the card slivers into a narrow lap for the comber.
The machine universally employed is termed "The Sliver Lap Machine," or, in some cases, "The Derby Doubler," and a modern machine is shown in the photograph forming Fig. 32.
In this case, eighteen cans are placed behind the machines, and the sliver from each can is conducted through an aperture in the back guide-plate designed to prevent entanglements of sliver from passing forward. Next each sliver passes over a spoon lever forming part of a motion for automatically stopping the machine when an end breaks. The eighteen slivers now pass side by side through three pairs of drawing rollers with a slight draft, and between calender rollers to a wooden "core" or roller. Upon this roller the slivers are wound in the form of a lap, being assimilated to one another by the action of the drawing and calender rollers.
