Improvements in Drawing Rolls for Machines for Working Fibrous Materials.
Year: 1893

page_text: Date of Application, 6th Nov., 1893—Accepted, 9th Dec., 1893
COMPLETE
SPECIFICATION.
Improvements in Drawing Rolls for Machines for Working Fibrous
Materials.
I, JAMES YATE JOHNSON of 47 Lincolns Inn Fields, in the County of
Middlesex, Gentleman, do hereby declare the nature of this invention (which has
been communicated to me from abroad by William Henry Goldsmith of Berkeley
in the State of Rhode Island, United States of America, Cotton Carder,) and in
what manner the same is to be performed to be particularly described and ascertained
in and by the following statement :-
This invention relates to drawing rolls for spinning frames, railway drawing
heads and drawing frames, and other machinery for working fibrous materials
and is applicable to metallic longitudinally fluted, or grooved, drawing rolls
used in pairs.
In ordinary "drawing heads" the bottom one of each pair of rolls is a grooved
or fluted metallic roll, and the top one is usually a leather covered roll which
furnishes a yielding surface to avoid injuring the sliver passing between the two
rolls. In some cases grooved or fluted metal rolls have been used for both top and
bottom rolls with the view of avoiding the expense consequent upon the employment
of a plain leather covered roll for the top roll. Where two fluted metal rolls are
employed however, the fibre passing between them is apt to be injured by being
tightly pressed into and against the bottom of the grooves of one roll, by the ribs
of the other roll. To obviate this objection it has been proposed, to provide
means such as collars mounted on the ends of one roll and arranged to bear against
circular bearing surfaces formed at the end of the other roll, these collars and
bearing surfaces being on the ends of the rolls outside of and beyond the flutes or
grooves whereby the rolls are held and maintained separated to such an extent that
the ribs of the one roll never enter the grooves of the other roll far enough to
contact with the bottom of said grooves.
It is the object of this invention to provide a simple and more effective way of
preventing injury of the fibre passing between fluted metal drawing rolls, dispensing
with the necessity of making entirely new rolls, and furnishing a construction to
which, at very slight expense, existing fluted metal drawing rolls can be readily
and expeditiously adapted.
According to this invention the grooves and ribs of the pair of rolls throughout
that portion of them which is in the path of the sliver, are so proportioned that
while the flutes at the two ends of the rolls mesh together in the usual way, and to
the full extent, so as to induce at all times positive motion by the direct positive
engagement of the one with the other, the central portion of the rolls, through
which the sliver passes has grooves and ribs of such size and so proportioned that
the ribs of the one do not extend to the bottom of the grooves of the other, but are
separated therefrom to such an extent as to perform their proper function without
crushing or unduly compressing the fibre. This result is preferably obtained by
making the grooves of the lower roll, throughout that portion of their length
which is in the path of the sliver, of greater depth than they are at the end
portions of the roll to each side of the central portion. In addition to deepening
the grooves the size of the ribs is also reduced throughout this central portion of
the roll so that it will be of less diameter than the end portions.
In the drawings
Figure 1 is a front elevation of a pair of drawing rolls embodying this invention

page_text: ure 4 is a front elevation and
Figure 5 is a section taken on the line 5-5, Figure 4, of a modification according
to this invention.
In the construction shewn in Figures 1, 2 and 3, the upper roll B is a metallic
fluted drawing roll of ordinary, or usual, construction. The lower roll A is a
metallic fluted roll, which so far as its end portions a are concerned is of ordinary, or
usual construction, the flutes on these end portions engaging directly and positively
at all times with the flutes of the upper roll. In the central portion b of the roll A
however, through which the sliver passes, the grooves are made deeper than they
are in the end portions, as seen in Figure 2, so that the ribs of the top roll will be
separated some distance from the bottom of this deepened portion of the grooves,
when the same ribs are against the botton of the shallower end extensions of said
grooves in the end portions a of the roll A. When the deepening of the grooves
is confined to one roll, then the ribs on that roll must be correspondingly cut away
so as to avoid bringing them in contact with the bottom of the grooves in. the other
roll. Consequently in the construction illustrated in Figures 1, 2 and 3 the ribs of
the lower roll are cut away so as to reduce the external diameter of that portion
of the roll in which the grooves are deepened.
In the construction shown in Figures 4, 5, the lower roll has its central portion
formed with deepened grooves, but is not reduced in external diameter; consequently
the grooves in the top roll B are correspondingly deepened, as shewn at b.
The main advantages of this invention are that it is applicable to existing fluted
metal drawing rolls, all that is needed being to deepen the grooves in one or both
of the rolls throughout the central portion 6; and that by this provision the con-
tinuous positive engagement of the rolls is permitted, thus causing the one to be
positively driven at all. times from the other, and avoiding uneven drawing of the
fibrous material which may occur where the power to drive the top roll is communi-
cated through the intermediary of the sliver; as the top or driven roll fouls in its
bearings, it is hard at times to drive, and consequently uneven drawing action will
result unless the two rolls engage directly together without any intermediary.
Having now particularly described and ascertained the nature of my said iuven-
tion and in what manner the same is to be performed, I declare that what I
claim is
-
1. A pair of longitudinally fluted drawing rolls, which engage together at their end
portions a, and at their central portion b, have their ribs and grooves so proportioned
that when the, ribs of the one roll meet the bottom of the grooves in the other roll
in the end portions a the corresponding ribs and grooves throughout the central
portion b will be separated from each other so that the ribs of the one will not
come into contact with the bottom of the grooves of the other throughout this
portion thus affording a path for the sliver, substantially as hereinbefore set
forth:
2. A pair of metal fluted drawing rolls in which one of the rolls throughout its
central portion 6 has deepened grooves, and is externally of less diameter than the
end portions a, substantially as and for the purposes; hereinbefore set forth.
Dated this 6th day of November 1893.
J. H. JOHNSON & Co.,
Agents.