Improvements in Bark Mills.
Year: 1889

page_text: Date of Application, 8th May, 1889
Complete Specification Left, 10th Feb., 1890-Accepted, 15th Mar., 1890
PROVISIONAL SPECIFICATION.
Improvements in Bark Mills.
I EDWARD VAVASOUR BROWN of Exeter, in the County of Devon, Engineer, do
hereby declare the nature of this invention to be as follows:-
This invention consists in the combination, in one machine, of chopping or
cutting mechanism with the grinding mechanism, which may be of the ordinary
type.
Parallel
In carrying out my invention, I arrange the bevel pinion above the bevel wheel of
the mill, and I prolong the pinion axle so that it extends across the mill.
with the pinion axle, I arrange a feeding apron, which is actuated by chain or other
gearing from the pinion axle. The apron receives the bark to be cut or chopped,
and delivers it to feed rollers, which present it to the chopping or cutting blade or
blades.
The chopping blade may be carried by the driving pulley, which may be larger than
usual, and also act as a fly wheel.
This pulley may be dish shaped, so that the bark, as it is chopped off and drops
down, may be thrown into the mill to be ground.
Means will also be provided whereby the chopped bark may, if desired, be projected
away from the mill, so that the chopping operation may be effected without the
grinding a course it is sometimes desired to take. In like manner, the feed apron
may be thrown out of gear, so that the grinding operation may be effected without
the chopping.
The long bark is simply laid in the feed trough, and requires no further attention;
the endless apron carries it forward to the chopper, where it is cut to suitable
lengths, and falls directly into the mill.
,
The self acting.feed removes all danger to the attendant, who may be a boy, as
all he has to do is to lay the bark on the apron, and the working parts are all covered
in out of harm's way.
The whole machine is self-contained, and of very strong design; it occupies less
space, and takes less power to drive than any other machine for reducing bark from the
long rind, while the feed being regular, the mill grinds much faster; and there is no
sudden strain upon the engine, as when heavy bark is suddenly fed into breakers by
hand.
The grinding is remarkably even, well ragged, and free from dust.
D13
4000
COMPLETE SPECIFICATION.
Improvements in Bark Mills.
I, EDWARD VAVASOUR BROWN of Exeter in the County of Devon Engineer, do
hereby declare the nature of this invention 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 a novel construction of bark mill, in which the bark is'cut
up transversely of the length of the fibre, and dropping from the cutting knives; is
received between the grinding surfaces of the mill, where it is further reduced to fit
it for the tanner's use

page_text: The object of the invention is to produce a simple, compact, and efficient
compound machine, which may be driven by a comparatively small expenditure of.
power
In the accompanying drawings,
Fig. 1 shows in side elevation, and Fig 2 in front elevation, my improved bark
mill, which may be set up upon any convenient framework, to give it the proper
elevation for discharging the reduced bark into a proper receptacle for the same.
A represents the casing of an ordinary conical bark mill, the central shaft A¹ of
which is stepped into a bearing carried by a cross bar bolted to the bottom flange of
the casting A, as usual.
The upper end of this casting is also flanged, and carries a pair of vertical
frames A A³, which are braced together by a cross piece fitted with a neck bearing
for the shaft A¹.
B is the driving shaft of the machine, having its bearings in the upper part of the
frames A³.
Mounted on one end of this shaft B, is the fast driving pulley C, and beside it a
loose band pulley. The fast pulley C is cup shaped in cross section, and fitted to its
hollow side are cutting blades c, similar to those used in chaff cutting machines. This
rotary cutter, mounted on the driving shaft, serves to sever the bark that is fed up to
it by a pair of feed rollers D, and acts also as the fly wheel of the mill. Keyed to
the driving shaft B is a bevil pinion B1, which gears into a crown wheel A³ keyed
to the upper end of the vertical shaft A', and through that wheel transmits rotary
motion to the conical runner of the mill.
E is a trough shaped casting secured by bolts to the frames A'
This trough lies parallel to the driving shaft, and it carries at its forward end
the feed rollers D, which serve to present the long strips of bark to the revolving
blades c The bottom of the trough E is filled up by an endless feed apron F
carried by rollers ff.
G is a shaft having its bearings in the back part of the frames A', and serving
to transmit motion from the main driving and cutter shaft to the travelling apron and
to the feed rollers
g. 1s a chain wheel keyed to one end of the shaft G, and gearing with an endless
chain carried by a chain wheel b on the shaft B.
g is a worm keyed on the shaft G, in gear with a worm wheel f' carried by the
axle of the endless apron roller f.
To this roller axle is also keyed a pinion f³, which transmits motion through an
idle pinion to a pinion d on the axle of the lower feed roller. To facilitate the
adjustment of the upper to the lower feed roller, the motion is transmitted from
the idle pinion just mentioned to a second idle pinion in gear with a pinion
the axle of that roller
on
The bearings of this roller slide in vertical slots formed in the trough casting E, and
they are held down by means of springs, which yield to any undue feed of the bark,
and thus prevent the choking of the machine.
The attendant standing at one side of the feed trough, lays the long rind or strips
of bark as evenly as may be on the travelling apron constituting the bottom of the
trough. The apron, in its steady travel, delivers the bark in an even and continuous
supply to the feed rollers, and these in turn present it to the revolving cutter
blades c.
From the foregoing description, it will be understood, that by moderate attention
on the part of the attendant, an even feed may be maintained throughout the
working of the machine. The consequence of this even feed will be a more rapid
and efficient action of the mill, and less liability than heretofore to a sudden strain
being put upon the motor engine, a result which is commonly occasioned by an undue
supply of bark being fed into the breakers by hand.

page_text: 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:-
The arrangement of cutting and grinding mechanism above described constituting
my improved compound bark mill.
DL: 1011
T000
NEWTON & SON,
Agents for the Applicant.