An Improved Leaf-stemming Machine.
Year: 1897

page_text: Date of Application, 7th Dec., 1897-Accepted, 5th Feb., 1898
COMPLETE SPECIFICATION.
An Improved Leaf-stemming Machine.
I, JOHN EDWARD EVANS-JACKSON, of 19 & 20, Holborn Viaduct, London,
Engineer and Patent Agent, do hereby declare the nature of this invention (com-
municated to me by William Henry Butler, of New York), 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 leaf-stemming machines, and is more especially
designed for removing the stems from tobacco leaves.
In the economy of nature, leaves are formed with stems from which the laterals
and the lamina or blade portions extend, and in each leaf the stem is of varying
diameter, thicker where it is attached to the stalk, and from thence tapering to
the point of the leaf. The lamina or blade-portions of leaves also vary in diameter,
being thicker and stronger at the base, and of tender and weaker structure at other
points.
"
In the plants of the genus Nicotinana" the leaves are provided with stems
which are thick and tough at the portion where they are attached to the stalk,
and are of varying thickness and strength from thence to the point; and it has
been a
problem how to remove such stems without damaging the portion of the
leaf which is useful and valuable in the art of tobacco manufacture. Heretofore,
various types of leaf-stemming machines have been employed, but owing to the
fact that they have acted with positive and unvarying pressure upon all portions
of the leaf, the thinner and more frangible portions thereof have been more or
less crushed, torn, or broken, and the results in all cases have not been satisfactory.
A leading object of my invention is the provision of means having a working
surface or surfaces of varying efficiency for removing stems from leaves; and
I consider as within the purview of the invention any and all devices and
mechanisms which operate upon the leaf with varying action, i.c., with an action
more forcible on one portion of the leaf than on another portion thereof, whereby
the stripping operation is accomplished with less danger of tearing or crushing
the thinner or more tender frangible portions of the leaf.
Another object of the invention is to furnish a simple and efficient tobacco
leaf-stemming machine shown in its preferred form as embodying rotative stripping
mechanism of improved construction and organization adapted for operating upon
successive portions of the leaf with a wiping action of successively-reduced pressure
commensurate with the reduction in thickness or tenacity of successive portions
of the leaf, whereby the thicker or more tenacious inner portion of the leaf will
be subjected to a wiping action of the relatively great pressure or force required
for separating this portion of the leaf body from the stem, and whereby the other
successive portions of the leaf of gradually-reduced thickness and tenacity will be
subjected to wiping actions of successively reduced pressures, to thereby remove the
wings of the leaf from the stem by a continuous wiping action of differential
pressure substantially proportionate to the thickness of the leaf and avoid the
possibility of skiving, tearing, or destroying any portion of the lamina or blade-
portion of the leaf.

page_text: A further object of the invention is to provide, in connection with leaf-feeding
mechanism of a tobacco leaf-stemming machine, two stemming-rolls having resilient
brush-like surfaces of decreased compactness or rigidity from the entrant end of
the rolls toward the exit end of said rolls, for the purpose of operating upon succes-
sive portions of the leaf with a wiping action of successively-reduced pressures, as
will be hereinafter more fully described.
In the drawings accompanying and forming part of this Specification, Figure 1
is a plan view of a tobacco-leaf stemming machine embodying one form of my
present invention, the stemming-roll being shown in this figure as conical and
having circumferent teeth of increased length from the entrant end toward the
exit end of said roll, said figure also showing three tobacco leaves substantially as
they appear at three different stages of the stemming operation. Figure 2 is a
front view, partially in section, of the tobacco leaf stemming machine shown in
Figure 1. Figure 3 is a front view of a portion of the framework of the stemming-
machine with the stemming-rolls removed, showing the construction and arrange-
ment of the feed mechanism. Figure 4 is a relatively large cross-sectional view
of a portion of the stemming machines taken on a line corresponding with the
dotted line a a, Figure 2, and looking toward the left hand in said figure. Figure 5
is a longitudinal section of the stemming-rolls shown in Figure 2. Figure 6 is a
plan view, partially in dotted lines, of one form of card-clothing, which may be
applied to, and constitute the brush-surface of, the stemming-roll. Figure 7 is
a cross-sectional view similar to Figure 5, of two conical stemming-rolls similar to
those shown in Figure 5, set with the larger end of one roll adjacent to the smaller
end of the other roll and having the operative face of the brush-surface of one roll
in parallelism with the face of the roll proper. Figure 8 is a longitudinal section
similar to Figures 5 and 6, of two co-operative stemming-rolls, one of which is
conical and has the teeth arranged in a spiral and of gradually-increased length
from the small to the larger end of said roll, and the other of which rolls is
cylindrical and has teeth circumferent to the working end, or in parallelism with
the axis of the roller. Figure 9 is a longitudinal section of two co-operative
cylindrical stemming-rolls set. with their longitudinal axes inclined relatively, and
which rolls are shown having circumferent teeth of gradually-increased length
in the direction of divergence of said rolls. Figure 10 is a longitudinal section of
a cylindrical stemming-roll having equidistantly-disposed circumferent teeth of
equal length but of gradually-decreased diameter and rigidity from one end
toward the other end of said roll; and Figure 11 is a longitudinal section of a
stemming-roll having circumferent teeth of substantially-corresponding lengths
and diameters, set closely together at one end and at gradually-increasing distances
apart toward the other end of said roll.
Similar characters designate like parts in all the figures of the drawings.
The tobacco-leaf stemming machine, in the preferred construction and organiza-
tion thereof shown in the drawings, comprises a suitable framework; feed
mechanism supported on the framework and effective for advancing the leaf and
for presenting the same to the action of the stemming mechanism; stemming
mechanism embodying two stemming-rolls operable for separating the body or
blade-portion of the leaf from the stem and having their co-operative faces of in-
creased pliability from the entrant end to the exit end of said rolls, whereby the
rolls will operate upon the leaf with a wiping action of decreased pressure as the
leaf passes from the entrant end toward the exit end of said roll; and means for
operating the rolls.
The framework of the stemming machine, which may be of any suitable general
construction for supporting the operative parts of the machine, and which is
designated in a general way by B, is shown comprising a triangular-shaped main-
body portion or bed 2, having suitable legs 3, 31, and 311, located one at each corner
thereof; uprights 4 and 4', located at opposite ends of the bed 2 and having
suitable bearings for supporting the rotative parts of the feed mechanism; bearing
brackets 5, 51, and 6, located on the bed and supporting the stemming mechanism;

page_text: and two bearing-plates 7 and 71, located preferably one above the other with their
adjacent faces in parallelism with, and adapted for controlling the pressure of,
the feed mechanism upon the stem of the leaf.
The feed mechanism, which is designated in a general way by F, is shown com-
prising two endless carriers or belts S and 12, located one above the other with
their adjacent runs between the two bearing-plates 7 and 71 and in close proximity
to one another; and driving mechanism for said carriers.
The upper carrier or belt 8 is shown supported at opposite ends of its upper and
lower runs upon drums or pulleys 9 and 91, whose shafts are journaled in suitable
bearings in the uprights 4 and 4' respectively; and the lower carrier or belt 12
is shown supported at opposite ends of its upper and lower runs upon drums or
pulleys 13 and 13 respectively, journaled at one end in a suitable bearing in the
upright 4, and at the other end in a bearing on the bracket 6, located at opposite
ends of the machine. The inner adjacent runs 8 and 121 of the two endless
carriers 8 and 12 are so disposed with relation to each other that the stem of the
leaf may be introduced between, and be grasped by, said runs for the purpose of
advancing the leaf and presenting the same to the stemming mechanism, as will
be hereinafter more fully described.
As a means for advancing the stem-engaging runs of the two endless carriers
in the same direction and at the same speed, the shaft 1311 of the pulley 13' is
shown furnished with a spur-wheel 14, which meshes with a spur-wheel 15, fixed
to the shaft 9 of the drum 91, and which shaft 9 is also provided with a driving-
pulley or belt-wheel 16, through the medium of which the pulleys 91 and 13' are
rotated in opposite directions in unison, said pulley 16 being driven from any
suitable source of power. (Not shown.)
It is desired to state in the above connection that the construction and organiza-
tion of the feeding mechanism may be variously modified within the scope and limits
of my invention, and that the leaves may be fed to the carriers by hand or in
any other desired manner.
The stemming mechanism, per se, which is designated in a general way by S,
comprises, in the preferred form thereof shown in the drawings, two co-operative,
super-imposed stemming-rolls 20 and 21, respectively, the shafts of the roll 20
of which is journaled at opposite ends thereof in suitable bearings 201 and 2011
in the bearing-brackets 5 and 51 respectively, and the lower roll, 21, of which has
its shaft likewise journaled in suitable bearings 21 and 21" in said brackets 5
and 5 respectively, said bearings being relatively separated to facilitate the un-
obstructed entrance between the rolls of the leaf or leaves to be operated upon
thereby.
By the terms entrant end" and "exit end" of the rolls is meant those ends
of the rolls where the first and last stages, respectively, of the stemming operation
are performed, the entrant end of the rolls being shown in Figures 1 and 2 at
the left-hand end of the machine and the exit end as at the right-hand end of the
machine.
In practice, the stemming-rolls 20 and 21 will set with their longitudinal axes
in vertical alinement and at an acute angle, horizontally, to the line of feed L L,
the entrant end of the rolls being set in close juxtaposition to the stem-grasping
portions or feed-runs 8 and 12 of the carriers 8 and 12, so that the leaf, as it is
advanced by the carriers, will be entered between the stemming-rolls in such
position that the co-operating brush-faces of the rolls will first act upon the
extreme inner or butt end of the body, or inner portion of the leaf, and said leaf
will be gradually drawn inward as the same is advanced from the entrant toward
the exit end of the stemming rolls, owing to the gradually-increasing distance
between the rolls and the carriers from the entrant to the exit end of said rolls,
as will be readily understood by reference to Figure 1 of the drawings.
For the purpose of constructing the stemming-rolls for operating upon the
successive portions of the leaf with a wiping action of gradually-decreased pressure
commensurate with the different thicknesses and tenacity of said successive portions,

page_text: so that the wings or blade portion of the leaf may be readily separated from the
stems by a continuous wiping action without injury to the leaf, said rolls 20 and 21
are furnished with brush-surfaces (designated by 25 and 251 respectively), the
construction and organization of said brush surfaces being such that they will
operate upon successive portions of the leaf with decreased bearing pressure pro-
portionate to the decrease in thickness or tenacity of said successive portions of
the leaf.
Inasmuch as it is possible to secure the results set forth in the last preceding
paragraph by the employment of various forms of stemming-rolls arranged in
various manners, and all of which rolls would necessarily embody the essence or
essential characteristics of my present invention, I have, for convenience, shown
several modified constructions and arrangements of stemming-rolls in the drawings,
and I wish it distinctly to be understood that my present invention is not limited
to the particular form of rolls or to the particular dispositions or arrangements
of the rolls shown in the drawings, as these may be variously modified without
departure from this invention.
In Figures 1, 2, 4 and 5 of the drawings, I have shown two superimposed,
conical rolls having brush-surfaces, the teeth of which intermesh and are of
gradually-increased length from the smaller to the larger ends of said rolls. In
this instance the leaf will enter between the rolls at the small ends thereof, said
small ends being adjacent to each other, and the co-operating brushes of the two
rolls will operate upon the leaf with a wiping action of gradually-decreased pressure
as the leaf passes from the entrant end toward the exit end of said rolls, owing
to the gradually-increasing flexibility of the teeth in this direction, due to the
- increased length of said teeth.
Furthermore, it will be seen from the construction shown in Figures 1, 2, 5
and 8, that as the leaf is passed between and from the small entrant ends of the
Folls toward the larger exit ends thereof said rolls act upon the leaf with different
peripheral velocities from the thicker toward the thinner portions thereof, thus
subjecting the thicker portions of the leaf to more energetic and forcible action
than the thinner portions thereof, and facilitating the operation of removing the
wings from the stem without liability of tearing the same, the surface speed and
the diameter of the successive portions of the rolls being such that the peripheral
velocities of the successive portions thereof will successively increase in accordance
with the reduction in tensile strength of the successive portions of the leaf, whereby
the thinner and weaker portions of the leaf are removed from the stem with in-
creased speed as compared with the thicker and stouter portions thereof.
In Figure 7 I have shown two superimposed, conical stemming-rolls set with
the small end of one adjacent to the large end of the other and having inter-
meshing brush-surfaces, the teeth of the brush-surface of the upper roll being of
increased length toward the larger end and those of the lower roll being of equal
length from end to end, the action of these brush-surfaces upon the leaf being the
same as the operation of brush-surfaces of the rolls shown in Figure 5.
In Figure 8 I have shown two superimposed stemming-rolls, the upper one of
which is conical and has spirally disposed circumferent teeth of gradually in-
creased length from the smaller to the larger end of said roll, and the lower roll
of which is cylindrical and of uniform diameter from end to end and has circum-
ferent teeth of equal length from end to end of the roll, which rolls perform the
same function as the rolls shown in Figures 5 and 7.
In Figures 9, I have shown two superimposed cylindrical rolls set with their
axes inclined relatively to one another and each having circumferent. brush teeth
of gradually-increasing length in the same direction from one end of said roll
to the other, the same space between the two rolls in this instance being tapered
from end to end.
In Figure 10, I have shown a cylindrical roll having circumferent teeth of
successively-decreased rigidity and of the same length and distance apart from end
to end of the roll, said teeth being of greater diameter at the entrant or left-hand

page_text: end of the roll and being of gradually-reduced diameter toward the opposite end
of said roll. This is adapted to be used in connection with a similar roll, and the
two rolls may be set with their axes in substantial parallelism.
In Figure 11, I have shown a cylindrical roll having teeth which are of sub-
stantially the same diameter from end to end of the roll, and which are set at
gradually-increasing distances apart from the entrant end toward the exit end of
said roll.
As a means for rotating the two stemming-rolls of the machine in opposite direc-
tions the shaft of the roll 21 is furnished with a gear 30, which meshes with a
gear 31 on the shaft of the roll 20, and this shaft is furnished with a driving-
pulley, which may be driven by a belt (not shown) deriving its motion from any
suitable source of power.
In practice, it is desirable to arrange the brush-surfaces of the two stemming-
rolls in opposite spirals and to drive the rolls and feed mechanism at comparative
speeds of predetermined velocities, so that the stem and body portion of the leaf
will be advanced by the feed mechanism and rolls respectively, in unison, the
spiral disposition of the wiping or brush surfaces of the two rolls acting as a screw
to advance the leaf body in unison with the feed mechanism.
In the drawings, the line of feed, which is represented by the dotted line L L,
Figures 5, 7, 8 and 9 respectively, is slightly inclined to a horizontal plane, but
it will be obvious that it might be substantially horizontal.
For convenience, the lower feed roll is shown supported in bearings which are
adjustable toward and away from the bearings of the upper roll, which bearings
may be of any suitable construction and adjusted in a suitable manner, said bear-
ings being herein shown supported in slideways and provided with set screws for
adjusting the same, the teeth of the intermeshing gears of the rolls being, in
practice, of sufficient. depth to facilitate the slight adjustment necessary. This
means of adjustment may, however, be variously modified.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is:-
1. In a leaf-stemming machine removing the web or wing from the stem by
passing the leaf between brushing or scraping rollers so arranged that the wiping,
brushing or scraping shall diminish in pressure as the leaf passes from butt end
to tip end between the rollers substantially as described.
2. In a leaf-stemming machine the arrangement of rollers and brush surfaces
as described and shown in Figs. 1, 2, 4, and 5, and also the various arrangements
of rollers and brush surfaces substantially as described and shown
Figs. 7, 8, 9, 10, 11 respectively.
in
3. In a leaf-stemming machine the general combination of parts consisting of
leaf-stemming rollers and leaf gripping devices and the means for actuating the
same, substantially as described and shown in the drawings.
Dated this 7th day of December 1897
J. E. EVANS-JACKSON & Co.,
Agents for the Applicant.