IMPROVEMENTS IN MACHINERY OR APPARATUS FOR PREPARING, CLEANING, AND CUTTING INDIA-AL-RUBBER AND GUTTA PERCHA
Year: 1854

page_text: LETTERS PATENT to John Macmillan Dunlop, of Manchester, in the
County of Lancaster, Engineer, for the Invention of "IMPROVEMENTS IN
MACHINERY OR APPARATUS FOR PREPARING, CLEANING, AND CUTTING INDIA-
PROVISIONAL SPECIFICATION left by the said John Macmillan Dunlop
at the Office of the Commissioners of Patents, with his Petition, on the
31st August 1854.
I, JOHN MACMILLAN DUNLOP, of Manchester, in the County of Lancaster,
Engineer, do hereby declare the nature of the said Invention for "IMPROVE
MENTS IN MACHINERY OR APPARATUS FOR PREPARING, CLEANING, AND CUTTING
INDIA-RUBBER AND GUTTA PERCHA," part of which is a communication from a
foreigner residing abroad, to be as follows:-
The first part of my improves relate to a method of freeing india-rubber
and gutta percha from dirt and other extraneous matters; to this end I employ
a revolving series of knives acting in combination with fixed knives, between
which two parts the material is caused to pass. The operating parts are placed
in a trough filled with water, in which the india-rubber or gutta percha is

page_text: placed, the whole apparatus being similar to a rag-cutting machine used in
paper making. The material by the above process is separated into shreds,
and may then be treated in any ordinary manner according to the purpose for
which it is designed.
The second part of my improvements relate to cutting india-rubber into
sheets from a block which has been obtained in a cylindrical form.
The block is caused to revolve by surface contact with a roller to which a
positive rotatory motion is imparted, during which. a reciprocating knife of
ordinary construction severs the required thickness of material. The block is
carried forward by the rotation of a screw, to which motion is given by a set
of change wheels, in order to regulate the thickness of the sheet, as may be
required; or, in place of this, the knife may be. gradually advanced. In order
to keep the surface roller in contact with the block as it diminishes in thick-
ness, I use a screw of suitable pitch, which screw is driven by the revolution
of the block; if, therefore, the friction surface fail in causing the material to
revolve, the feed will necessarily cease.
In
I also effect the advance of the surface roller by means of weights.
contact with the block I place a roller, and in such a position that a line
drawn through the two centres will pass through the point (or nearly so) at
which the material is severed.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John Macmillan Dunlop in the Great Seal Patent Office on
the 28th February 1855.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
MACMILLAN DUNLOP, of Manchester, in the County of Lancaster, Engineer,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Thirty-first day of August, in the year of our Lord
One thousand eight hundred and fifty-four, in the eighteenth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said John Macmillan Dunlop, Her especial license that I, the said John
Macmillan Dunlop, my executors, administrators, and assigns, or such others as
I, the said John Macmillan Dunlop, my executors, administrators, and assigns,
should at any time agree with, and no others, from time to time and at
all times thereafter during the term therein expressed, should and lawfully

page_text: might make, use, exercise, and vend, within the United Kingdom of Great
Britain and Ireland, the Channel Islands, and Isle of Man, an Invention for.
"IMPROVEMENTS IN MACHINERY OR APPARATUS FOR PREPARING, CLEANING, AND
CUTTING INDIA-RUBBER AND GUTTA PERCHA," partly a communication from a
foreigner residing abroad," upon the condition (amongst others) that I, the said
John Macmillan Dunlop, by an instrument in writing under my hand and
seal, should particularly describe and ascertain the nature of the said Inven-
tion, and in what manner the same was to be performed, and cause the same
to be filed in the Great Seal Patent Office within six calendar months next and
immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said John Macmillan Dunlop, do hereby
declare the nature of the said Invention, and in what manner the same
is to be performed, to be particularly described and ascertained in and by the
following statement and accompanying Drawings, that is to say :-
These improvements in preparing or cleaning india-rubber and gutta percha
consist in the employment of rotatory and fixed knives, between which the
material is caused to pass after the manner of a rag-cutting machine as used
by paper makers. The improvement for cutting the aforesaid materials into
sheets relates to machinery for operating upon a cylindrical block thereof.
And in order that the same may be fully understood, I have appended to
this my Specification two Sheets of Drawings, which I will now proceed to
describe.
The machine for preparing Or cleaning is shewn in plan or horizontal view
at Fig. 1, and in section at Fig. 2. Within a vessel a, partly divided by a
partition d, is placed a cylinder b, the axis of which is caused to revolve by any
suitable application of motive power. This cylinder is provided with a number
of projecting knives c, keyed therein; and beneath is situate a series of fixed
knives e keyed into a stationary framing f, and placed at an angle with those
upon the cylinder, so that the latter, in passing nearly in contact with the
former, assume the relative positions of shear blades; or, instead of this precise
arrangement, the knives upon the cylinder may be placed at an angle to its
axis, or both sets may be so mounted. The vessel a is to be continuously
supplied with clean water, and the material being placed therein will be drawn
downward and carried between the rotatory and fixed knives, after passing from
which it will be conveyed by the fluid current round the partition d, again to
be operated upon as before; and so on, until the required treatment shall have
been completed. The cylinder b is mounted so as to be capable of being raised.
or lowered, in order to bring the two sets of knives nearer to or further from

page_text: l
cach other, and the dirty water is allowed to pass off through a grating, which
prevents the india-rubber or gutta percha from escaping. The machine for
cutting cylindrical blocks into sheets of india-rubber or gutta percha is shewn
in side elevation in Fig. 3, and in plan view at Fig. 4. The main driving shaft
is shewn at a, upon which there is a pinion 6 communicating rotatory motion
to a shaft c provided with a worm d, which worm is mounted loosely, but is
caused to revolve by means of a groove and feather, and is in gear with a
wheel mounted upon the axis of a roller f; the bearings g, g*, of this roller
are formed so as to be capable of sliding in a parallel direction upon guides on
the top of the framework h, and the lower end of one of them carries the
worm d, which is therefore caused to travel with it by sliding upon its shaft.
The cylindrical block of material required to be cut into a sheet or sheets is
shewn at i, mounted upon an axis j carried by bearings h, k, which are also
mounted so as to slide along the framework. The axis j is provided with a
bevil pinion communicating motion to a shaft m, which carries a pinion n,
taking into a wheel o affixed to a screw p, which screw is situate within a nut q
formed upon the sliding bearing 9. Attached to the screw p is a wheel r, com-
municating motion, as shewn in the Drawing, to an equal wheels, mounted
fast upon a screw p*, situate within a nut q, formed upon the sliding bearing g",
and by these means the two screws are caused to revolve at equal velocities, so
as to traverse the nuts 7, 9*, parallel to each other. The screws p, p*, are con-
tinued so as to extend into nuts t, t*, formed upon the bearings k, k*, of the
block of material i, but are there formed with threads of half the speed. The
pinion is mounted loosely upon the shaft m, but is caused to revolve there-
with by means of a groove and feather; as, therefore, the bearings k, k*, slide
upon the framework, the wheels o, s, will still be caused to revolve, the driving
power still being maintained by reason of the bevil wheel l* being carried by
the block h. Upon the main shaft is mounted a cam or excentric which com-
municates a rapid reciprocating motion to a sliding piece u, upon which is
formed a plate v carrying a knife w situate just above a roller x, the peri-
phery of which is in contact with the cylindrical block i, and in such a position
that the centres of the two continue on the same plane during the cutting of
the material. In order to prepare the machine for operation, a winch handle
is to be placed upon one of the wheels r, s, so as to draw back the bearings
k, k, to the necessary position to receive the axle j, with its block i; after this
a winch is adapted to a transverse shaft y, which shaft is provided with worins
y taking into wheels affixed to the nuts q, q, which being by these means
caused to revolve, the bearings 9,7*, which carry them will be caused to slide

page_text: forward, and bring the roller f into contact with the block i, and with the
required amount of pressure. Upon motion now being communicated to the
driving shaft, the worm and worm wheel d, e, will cause the roller f to revolve,
and impart by contact of surface the like motion to the block i, which as it
rotates will be operated upon by the reciprocating knife to, and will, through
the medium of the gearing described, cause the screws p, p, to turn in their
nuts, so as to slide the bearings k, k", onward, and effect the necessary feed for
continuous cutting; the turning of the screws p, p, will at the same time operate
within the now stationary nuts 9, 2*, thereby carrying forward the roller f, so
as to maintain its relative position with the block i; in order, however, that
this may be effected, it is necessary that the roller f should advance at a rate
double to that of the block i, and it is for this purpose that the threads of the
screws are formed of the relative speeds above described. It will be observed
from the foregoing that the motion for effecting the feed is gained by the revo-
lution of the block i; should the surface roller f, therefore, fail in causing it
to rotate, its advance towards the knife will also be arrested. Upon the block
having been cut up to the required extent, the roller f may be moved back-
ward by applying a winch handle to the shaft y, as above described, and
another block adapted. In order to regulate the advance of the material for
any required thickness of sheet to be severed, the pinion n and wheel o may
be changed so as to alter the rate of revolution of the screws. For the purpose
of facilitating the cutting, actream of water is directed upon the knife w from
any convenient source. The mounting of the cylindrical blocks of material
upon their axes may be effected in any suitable manner, but a method I adopt
is to place the axes within moulds, and then by pressure, and with or without
heat or steam, squeeze the material around them.
Having thus described and ascertained the nature of the said Invention, and
the manner in which the same is to be performed, I desire it to be understood,
I do not confine myself to the precise arrangement and construction of parts
shewn, particularly in reference to the roller f; I would observe that, if desired,
it may be caused to maintain its contact with the block i by means of weights,
but I claim as secured to me under the above in part recited Letters Patent
the use of rotatory in combination with stationary knives for the purposes of
preparing and cleaning india-rubber and gutta percha.
In reference to the cutting of cylindrical blocks of the like materials into
sheets, I claim,-
Firstly, imparting rotatory motion thereto while cutting, by means of a
surface roller or rollers.

page_text: Secondly, deriving the feed or advance motion from the revolution of the
material under operation.
And, thirdly, the application of the roller above described and shewn at æ.
In witness whereof, I, the said John Macmillan Dunlop, have hereunto
set my hand and seal, this Twenty-seventh day of February, in the year
of our Lord One thousand eight hundred and fifty-five.
JOHN M. DUNLOP. (L.B.)