SPINNING.
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doffing without stopping the drawing frame or carding engines. When one coil isfilled, the finger, b, is just brought over to the other spindle, so that the full coil isstopped, and the new one begins to be formed without the slightest interruption of themachine.
Mr. B. forms coils in various ways, also in cans; but this description is sufficient toshow the application of this mode of winding up bands or rovings. Several of the above-described machines are adopted with equal success to wool and flax. In his patents of1835, 1837, and 1838, he shows several modes of applying his system to cotton and othermachinery. He winds directly from the carding engines the slivers separately upon longbobbins, and he gives'them twist in two directions, for the purpose of uniting the fibresto some extent, so that they not only come off the bobbins without sticking to oneanother, but also that they may draw smoother. He also showed a machine, by whichseveral rovings, say 4 or more, are put upon the same bobbin with conical ends ;these bobbins are placed behind the mules or throstles, and are unwound by a belt orstrap running parallel with the fluted rollers of the spinning machine, as seen in fig. 147.The belt or band, A, is worked in a similar way to that described in his former patent,and the bobbins, B, rest upon and revolve upon their surface, exactly according to thespeed of the belt. It is quite evident that the whole set of rovings must be unwoundexactly at the same speed, and that no stretching can take place. He can put real andreversed twist in these rovings as well as false twist only. The most important featurein the roving machine is a metal plate, in which a slot is formed through which therovings pass; this slot is seen in figs. 148,149, and 150. The cotton, when coming from
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the drawing rollers, is passed through the twisters, C, and through the slot in the plate, D.Thus he is-enabled to put any convenient number of neatly formed and perfectly sepa-rate coils upon the wooden barrel or bobbin. The bobbin formed upon these machinesis represented in fig. 151, and the conical ends are formed by a mechanism, by whichthe twisters, C, are caused to approach a little more to one another, after each layer ofrovings has been coiled round the barrel: the section of the bobbin is therefore likethat shown in fig. 151. He makes use of exactly the same arrangement, viz., a fingertravelling along a slot in a plate, for the purpose of forming the coils, which has beenalready described.
Roving? wound upon bobbins by means of tubes revolving in one direction, are cer-tainly not so fit for spinning as rovings into which a small degree of twist is put. Thetube by which a twist is put in on one side and taken out at the other, curls or ruffles