is
led from its sliver can at the far side of the machine to the sliver
guide and between the retaining rollers. Immediately the slivers
leave the retaining rollers they are penetrated by the gill pins of
a faller which is rising from the lower part of its circuit to the
upper and active position. Each short length of slivers is
penetrated by the pins of a rising faller, these coming up
successively as the preceding one moves along at approximately the
same surface speed as that of the retaining rollers. The sheet of
pins and their fallers are thus continuously moving towards the
drawing rollers and supporting the slivers at the same time. As each
faller in succession approaches close to the drawing rollers, it is
made to descend so that the pins may leave the fibres, and from this
point the faller moves backwards towards the retaining roller until
it reaches the other end ready to rise again in contact with the
fibres and to repeat the cycle as just described. It will thus be
seen that the upper set of fallers occupy the full stretch between
the retaining rollers and the drawing rollers, but there is always
one faller leaving the upper set at the front and another joining
the set at the back.

[Illustration: Fig. 17 Push-bar drawing frame]

The actual distance between the retaining rollers and the drawing
rollers is determined by the length of the fibre, and must in all
cases be a little greater than the longest fibre. This condition is
necessary because the surface speed of the drawing roller is much
greater than that of the retaining rollers; indeed, the difference
between the surface speeds of the two pairs of rollers is the actual
draft.

Between the retaining and drawing rollers the slivers are embedded
in the gill pins of the fallers, and these move forward, as mentioned,
to support the stretch of slivers and to carry the latter to the nip
of the drawing rollers. Immediately the forward ends of the fibres
are nipped between the quickly-moving drawing rollers, the fibres
affected slide on those which have not yet reached the drawing
rollers, and, incidentally, help to parallelize the fibres. It will
be clear that if any fibre happened to be in the grip of the two
pairs of rollers having different surface speeds, such fibre would be
snapped. It is to avoid this rupture of fibres that the distance
between the two sets of rollers is greater than the longest fibres
under treatment. The technical word for this dis