IMPROVEMENTS IN COTTON GINS
Year: 1885

page_text: COMPLETE SPECIFICATION.
I, HERBERT JOHN ALLISON, of the firm of Allison Brothers, Patent Agents, of
52 Chancery Lane, London, in the County of Middiesex, do hereby declare the
nature of my invention for "IMPROVEMENTS IN COTTON GINS,"-communicated
to me from abroad by Charles Thomas Mason, Junior, of Sumter, South Carolina,
United States of America, and in what manner the same is to be performed, to
be particularly described and ascertained in and by the following statement:-
The form of cotton gin in most common use, is that known as the "saw gin." It
consists essentially of a number of fine toothed rotary saws, the teeth of which
project through slits or openings into a chamber in which the cotton to be cleansed
is placed. The teeth serve to draw out the fibres of the cotton, the seeds and
foreign substances being retained in the chamber.
Various improvements in the form and construction of the cotton gin have been
made without however obviating in marked degree, many well known difficulties
and disadvantages incident to its use. Among the latter may be enumerated,
(1) high cost of manufacture; (2) need for frequent and expensive repair owing to
the dulling and breaking of the saws or of the ribs; (3) the constant care required
in properly spacing saws and relatively adjusting the ribs both in respect to thick-
ness and position, the removal of any one saw necessitating readjustment of the
entire series; (4) choking of the thin spaces between the ribs; (5) liability of two
saws operating in the same space and thus cutting and breaking the cotton fibre
into short lengths; (6) engagement of the teeth with foreign matters in the lint,
and consequent drawing of such matters through the slits and mixing of the same
with the ginned cotton; (7) danger from fire owing to the saws striking stones,
nail or like hard substances in the cotton and consequent high insurance rates,
and serious conflagrations and losses; (8) liability of breakage of saws and ribs
owing to the presence of aforesaid foreign substances and contact of the rapidly
rotating saws therewith.
My present invention has for its object to overcome all of those difficulties either
completely or in greater degree than has hitherto been attained. I define its
principle as follows: to construct a ginning cylinder having teeth which shall seize
Prins C11

page_text: a
only the cotton fibre and not the seeds, or other relatively hard foreign substances
contained in the mass presented to its action, and shall strip or remove the cotton
fibre wholly or in great degree from said seeds. By "ginning cylinder "I mean
cylindrical body for drawing out the cotton lint from the seed cotton to be
substituted in place of the aggregation of saws now used in an ordinary gin as
above outlined. I have discovered that the before mentioned result can be
accomplished by means of a cylinder having a hard periphery, in which periphery
are numerous openings and in each of which openings is secured a tooth fixed at
one end, extending in said opening in a circumferential direction with reference to
the cylinder, provided that the position of the free points or ends of said teeth shall
approximate to the circumadjacent level or surface of the periphery of cylinder,
the said cylinder being rotated so that the teeth shall be presented points forward
to the cotton.
It is requisite also that there shall exist in front of and on each side of the end
or point of each tooth a space or opening into which the lint by reason of its
softness and elasticity may enter when the cotton is placed in contact with the
surface of the cylinder; and into which space the seeds or hard foreign material
not being soft and elastic cannot enter and into which the seeds are also prevented
from entering by reason of their size.
When a cylinder provided with teeth arranged as described, that is, openings in
the periphery and with their points disposed very slightly above, on a level with
or very slightly below the immediately circumadjacent portion of said periphery,
then by simply causing the cotton to lie in contact with said cylinder when
rotating, with the points of the teeth forward, the lint will by its own elasticity
enter the openings around the teeth in a radial direction toward the axis of the
cylinder, and will be engaged and drawn out by said teeth, while the hard bodies
such as the seed and foreign matters will not be so engaged.
In order to strip the seed clear I find it is desirable to give the tooth an actual
thrust directly into the soft proximate coating of the seed, by reason of the rotation
of the cylinder-so that the said tooth may reach the hard surface and then draw
the fibre clear and clean from the latter. In order to do this, space must be
afforded not merely in front of and at each side of the point of the tooth as thus
far described, but also beneath the tooth so that its point may be free to be pushed
directly into the mass; or conversely, so that the cotton may enter below said point
in a direction tangential to the circumference of the cylinder. I can accomplish
this result in different ways, while still adhering to the requirements of the
invention (that the points of the teeth must closely approximate the general level
of the circum.adjacent portions of the cylinder.)
It is important, to notice however, that if an elevation of the points of the teeth
is resorted to, said elevation must not be such as to enable them to engage directly
with any hard body-and if in practice this is found to be the case, then the points
are set too high and must be depressed or lowered. I can accomplish the desired
result by (1) slightly elevating the points above the general surface of the cylinder
or (2) by leaving the points of the teeth at the level of the general surface of the
cylinder and slightly depressing a small portion of the surface immediately in front
of them; or (3) I can make the surface of the cylinder corrugated in comparitively
sharp curves and cause the points of the teeth to lie on the general level of the
corrugations along which they are disposed, in which case, the outer ends of the
openings will radially be nearer the axis of the cylinder than the points, and
hence the cotton can enter said openings in a tangential direction and so meet the
points.
In the accompanying drawings I show the three modes above referred to of
carrying out my invention into practicable effect.
In Figures 1 to 3 inclusive is shown a corrugated cylinder and the same applied
to the usual form of gin.
In Figures 4 to 6 inclusive is shown a cylinder having slight depressions in front
of the teeth, also applied to the usual form of gin.

page_text: In Figures 7 to 14 inclusive is shown a cylinder having straight or tangential
teeth, applied as before to the usual form of gin together with detailed views of the
teeth and cylinder.
In each case the toothed cylinder constructed in accordance with my invention is
applied to a gin in a similar manner so that the gin represented in Figures 1, 4,
and 7 is the same apparatus in each figure, the letters of reference corresponding
and indicating like parts.
I will first describe the mode of construction of the gin-frame and other parts
represented in said figures 1, 4 and 7.
A is the grate fall or breast hinged to the main frame at a. B is the back-board.
C is the seed board and D the brush for receiving the lint from the cylinder. E is
the ginning cylinder which in the machine occupies substantially the same position
as the saw gin cylinder in common use, the grate grid or ribs being removed and a
bar F secured in the concave c. This bar I make preferably of steel-in operation
it should be adjusted near to the surface of the cylinder E. I have found 1/16 inch
to be a good working distance. The grate fall or breast A being hinged as already
stated is adjustable nearer to or farther from the frame, and as the bar F is secured
in said breast the movement of the latter may bring said bar nearer to or farther
from the cylinder surface. I show no means of securing the breast A in different
positions as adjusted, but these will readily suggest themselves.
The cylinder E in Figures 1, 4 and 7 is made of sheet or thin plate metal G
preferably steel. It is provided at the ends with heads or discs of wood, which are
secured in any suitable way to a sleeve h. adapted to receive the splined shaft I.
This cylinder E is provided with slots o, containing pointed teeth g, and the
construction of this cylinder may be varied in either of the ways represented in
Figures 1, 4 and 7; the result produced in each case by the action of the cylinder
on the cotton being the same.
So also the operation of the machine is the same with either construction of
cylinder. The seed cotton is placed in the receptacle K, Figures 1, 4 and 7 and
meets the toothed surface of the cylinder E, which rotates in the direction of the
arrow 4. The teeth upon said cylinder engage only with the cotton lint as already
described and carry the same past and under the bar F which prevents seeds and
other foreign substances being drawn around the cylinder with the lint. As the
cylinder continues its revolution the lint is removed from its teeth by the brush-
wheel D from which the cleansed material passes out of the machine in the direction
of the arrow 5.
I will now describe in detail the three modes of constructing the toothed
cylinder E.
Referring first to the arrangement and construction of the device shown in
Figure 1. Figure 2 is an elevation of the gin cylinder E, which has a corrugated
periphery. Figure 3 shows a portion of the periphery of said cylinder in section,
enlarged.
The thin sheet of metal G forming the periphery of the cylinder E is here
longitudinally corrugated and a row of slots or openings o is formed in each of said
corrugations. The pointed tooth g, in each slot or opening o conforms to the curve
of the corrugation. The points of the teeth are disposed at or about the level of
the general surface of the saw corrugation. By reason of each tooth being tapered
and pointed and arranged in the slot, there is an open space in the periphery of the
cylinder, extending directly in front of the point of the tooth and on each side of
the body thereof. Into this opening the lint (because of its elasticity and softness)
can enter in a radial direction, towards the axis of the cylinder when brought into
contact with the periphery of said cylinder.
From Figure 3, it will be seen that the radius of the curve of each corrugation is
shorter than the radius of the general circumference of the cylinder, and also that
the edges of each corrugation are nearer the axial centre of the cylinder than tho
central or middle portions of said corrugations.

page_text: Or in
Consequently each of said slots o will have its outer extremity 2, nearer said
axial centre than the portions of said slot which extend on each side of the
contained tooth and hence the lint may enter said slot, not only in a radial but
also in a tangential direction, as indicated by the arrows 1 and 2, Figure 3.
other words when the cylinder E is rotated the point of each tooth will be thrust
directly into the coating of the seed for a short determinate distance before it
begins to draw the fibre from the body of said seed.
Referring next to the form of my invention shown in Figure 4; Figure 5 is an
elevation of the cylinder separately and Figure 6 is a section of a portion of the
periphery of said cylinder showing the arrangement and disposition of the teeth.
Instead of making the cylinder E of corrugated form as previously described,
I make it cylindrical and substantially smooth. The pointed teeth g are integral
with the sheet as before and the general arrangement of parts is the same and is
designated by like letters of reference as in Figures 1 to 3 inclusive.
In order that the point of each tooth may penetrate the exterior fluffy coating
of the seed by a direct thrust or in other words in order that the cotton surrounding
said tooth may meet the same in a direction tangential to the circumference of the
cylinder, I form in the periphery of the latter and in front of the points of each
row of teeth, longitudinal depressions J. These recesses are very shallow, but when
they are present the cotton surrounding the seed enters them and in this way, as
shown in Figure 6, is presented to the front of the tooth, which when the cylinder
is rotated, thus is free to pentrate directly for a certain distance into the covering
of the seed, before it begins its drawing action on the fibre.
.
The form of my invention which is represented in Figure 7, is shown in detail in
Figures 8, 9, 10, 11, 12, 13 and 14.
The general construction is the same as already described and similar letters of
reference indicate like parts.
Figure 8 is an elevation of the ginning cylinder.
Figure 9 is a section on the line x, x, of Figure 8.
Figures 10 and 11 are views explanatory of the mode of arranging the teeth.
Figure 12 represents one of the sections of which the cylinder shown in Figure 8
is composed.
Figure 13 represents one of the openings in said cylinder and its contained
tooth enlarged, and Figure 14 represents a portion of the periphery of the cylinder.
The cylinder E as in preceeding examples, consists of a sheet of thin plate
metal G, preferably of steel which is bent in a cylindrical shape having its meeting
edges secured around heads or discs preferably of wood. Said cylinder may consist
of a number of smaller cylinders or sections M, one of which is represented
separately in Figure 12.
In the plate G are the slots or openings o containing pointed teeth g.
The distinctive features of this mode of construction represented in Figures 7
to 14 is that the openings and teeth in the sheet G are made with the sheet flat.
When the sheet is bent in cylindrical form the tooth being attached only on one
end, will not naturally partake of the curved shape of the bent sheet but will
remain straight, or in other words, will remain tangential to the circumference.
Figures 10 and 11 are intended to exhibit plainly the difference between teeth bent
to follow the curve of the cylinder (Figure 10) and those left straight as above
described (Figure 11).
In Figure il it will be seen that the straight teeth have their points L slightly
above the general surface of the cylinder. I find in practice that this protusion
should be about one half the thickness of the teeth when the sheet is made of
Number 20 or 22 sheet steel.
A good general test for setting the teeth is that the points of the teeth should
just be met by the edge of a knife blade when the blade is laid flatwise on the
periphery of the cylinder and immediately in front of said points.
It will be seen that by this construction the teeth are straight or tangential to
the curve of the sheet or plate. By referring to Figures 10 and 11 it will be

page_text: apparent that when the cylinder rotates in the direction of the arrow 1, the cotton
may enter the space around the point radially in the direction of the arrow,2.
From Figure 11 it will also be obvious that the cotton enters not only radially in
the direction of the arrow 2, but also tangentially and beneath the point in the
direction of the arrow 3; so that the point L is in fact thrust in the direction of its
length into the cotton before the drawing out of the fibre begins. The elevation of
the point is however so slight as not to enable it to engage with hard foreign
substances in the cotton while on the other hand it is sufficient to allow it to
penetrate, as already stated, through the soft covering of the seed before drawing
out the fibre as the rotation of the cylinder continues.
I have found by experiment there is a special advantage in constructing the slots
and teeth as more particularly shown enlarged in Figure 13 of the drawings. That is
to say I make the said openings of V shape so that the teeth are formed by the solid
middle portion of the V. The reentering angle i of the V in front of the point L
of the tooth I make rounded or concave, in preference to acute because a wider and
more uniform area is afforded for the cotton to enter, than could be the case were
the angle sharply carried out, as indicated by the dotted lines. It is obvious that
with such an acute angle the cotton would have to enter into a very narrow space
near the apex thereof, and besides this in such a wedge shaped space the river is
easily caught or jammed. This rounding of the re-entering angle of the V (and at
the same time substantially cutting off its apex) also allows of a wider longitudinal
rib of cylinder surface being left between the parallel series of slots, than would be
the case with sharp angled openings having the same area of effective space into
which cotton could enter; so that the cylinder periphery especially when made of
thin metal is thus strengthened.
It will be noticed that the outer ends l, m, of converging parts j, k, of the V shaped
openings are also made round or concave. The advantageous result here is two
fold. First, the cotton is prevented from becoming wedged between the side of
the base of the teeth and adjacent portions of the periphery, and second, the
lines o, p, of junction of base of tooth and main portion of the periphery are curves,
so that the base of the tooth gradually enlarges, rendering the teeth stronger at
this point, and avoiding the danger of breakage by tearing as might be the case if
the sides of the teeth made a sharp angle with the adjacent parts from which the
tooth extends.
With the same object of avoiding a wedge-shaped opening, I make the width of
each aperture, on each side of the tooth equal and uniform from the point where
the base curve of the tooth stops (or from the rounded or concave extremity of each
aperture) to the point of the tooth. That is to say, the edges or sides of the teeth
on one side of the openings and the opposite edges of the material of the cylinder
on the other side should be parallel. Whenever sharp wedge-shaped apertures exist
in cotton ginning cylinders, the lint will jam or be caught in them, and the brush-
wheel is apt to fail properly to clean the cylinder, and hence the importance will be
apparent of constructing said apertures as much as possible free from tapering or
converging portions. This principle I have embodied in the forin of opening and
teeth above described.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is
First. A cotton ginning cylinder having in its periphery openings, and in each of
said openings a tooth extending in a circumferential or approximately circumferential
direction, having the point disposed at or closely approximating the level of the
general surface of said cylinder.
Second. A cotton ginning cylinder having upon its periphery teeth extending in
a circumferential or approximately circumferential direction each tooth being secured
at one end and having its point at or closely approximating the level of the general
surface of said cylinder and a cotton receiving opening in said periphery immediately

page_text: surrounding said point wherein the cotton can enter in a direction tangential to the
circumference of said cylinder and also in a radial direction.
Third. A cotton ginning cylinder having in its periphery openings and in each
of said openings a tooth having its point at or closely approximating the level of
the general surface of said cylinder, the said tooth being straight, flat or tangential
to the circumference of the cylinder.
Fourth. In a cotton gin, a cotton ginning cylinder having in its periphery a series
of V shaped openings, each opening forming a slot or recess with a contained tooth
constituting the solid middle portion of the V, the outer ends of the converging
portions of said openings being rounded or concave and the widths of said portions
being substantially uniform on each side of the tooth.
Fifth. In a cotton gin, the combination of a stationary retaining bar or plate for
the material to be acted upon and a rotary cylinder having in its periphery
openings and in each of said openings a tooth having its point disposed at or closely
approximating the general surface of said cylinder.
Sixth. In a cotton gin, the combination of a receptacle for the seed cotton, a
retaining bar or plate for the same and a rotary cylinder having in its periphery
openings and in said openings teeth extending in a circumferential or approximately
circumferential direction, having their points disposed at or closely approximating
the general surface of said cylinder.
Seventh. A cotton ginning cylinder having in its periphery openings and a tooth
in each opening and lying in a circumferential direction, the said tooth having its
body conforming to the curve of the periphery and its point at or about the level
of the general surface thereof and a shallow recess or depression in said periphery
at or near the point of said tooth.
Eighth. A cotton ginning cylinder having a corrugated slotted periphery, provided
with teeth located within said slots and having their points disposed at or about
the level of the circum-adjacent surface of said periphery.