A CERTAIN IMPROVEMENT OR IMPROVEMENTS IN THE METHOD OR METHODS OR MACHINERY EMPLOYED FOR SHEARING OR CROPPING WOOLLEN CLOTH
Year: 1821

page_text: SMITH, of Hackney, in the County of Middlesex, Gentleman, send greeting.
WHEREAS His present Majesty King George the Fourth, by His Letters
Patent under the Great Seal of the United Kingdom of Great Britain and
Ireland, bearing date at Westminster, the Eighteenth day of April now last
past, did give and grant unto me, the said James Smith, His especial licence,
that I, the said James Smith, my executors, administrators, and assigns, and
such others as I or they should agree with, and no others, during the term of
years therein expressed, should and lawfully might make, use, exercise, and
vend, within England, Wales, and the Town of Berwick-upon-Tweed, my
Invention of "A CERTAIN IMPROVEMENT OR IMPROVEMENTS IN THE METHOD OR
METHODS OR MACHINERY EMPLOYED FOR SHEARING OR CROPPING WOOLLEN CLOTH ;'
in which said Letters Patent there is contained a proviso obliging me, the
said James Smith, by an instrument in writing under my hand and seal,
particularly to describe and ascertain the nature of my said Invention, and in
what manner the same is to be performed, and cause the same to be inrolled
in His Majesty's High Court of Chancery within six calendar months next
and immediately after the date of the said Letters Patent, as in and by the
said Letters Patent, reference being thereunto had, will more fully and at large
appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
James Smith, do particularly describe and ascertain the nature of my said
Invention, and the manner in which the same is to be performed, in manner
and form following, that is to say:-

page_text: My said Invention consists in an improved form or construction given to
the revolving steel cutters in those machines employed for shearing or cropping
woollen cloth, which operate by the action of such cutters against what is
known in such machines by the name of a ledger blade. And the said
improved form or construction consists in winding one, or two, or three, or a
greater number of cutting bars or blades round a cylinder, in such a manner
that the said cutting bars may each form a proper shearing angle with the
ledger blade, against which they are brought successively in action by a rotary
motion, communicated to the cylinder by the power employed to work the
machine. (But I prefer three such bars parallel to each other, and consistently
with such preference shall, in the remainder of this description, speak chiefly
of three such bars or blades used as described.) Between each cutting bar
and the one next to it there is an interstice, the depth of which depends on
the thickness of the cutting bars or the height of their faces above the surface
of the cylinder on which they are fastened, which surface forms the bottom of
the said interstices... A'.perfectly correct idea may be formed of the shape of
the cylinder when mounted with its cutting bars, by.conceiving it to be a screw
of three or a greater number of threads, according to the number of cutting
blades, each cutting blade: forming one of the threads. In practice I have
found it best in preparing the cylinder with its cutting blades to cover the
cylinder with a double set of cutting blades, which being properly fitted to and
fastened upon the cylinder, their .outer surfaces are then turned and made
perfectly cylindrical; they are then to be removed from the cylinder and
hardened, and after they are.so hardened they must-again be placed upon the
cylinder, and any irregularity which may have been occasioned by the
hardening must be corrected with a grinding tool. When the outer surfaces
of, the said blades. have been thus perfected or made truly cylindrical, every
second.cutting blade.is: taken out and kept.in reserve, to be used when those
.that are left in their own. places may be worn out...Respecting the length and
diameter, of the, cylinder, and the thickness and breadth of the cutting blades,
considerable.latitude may. be used. according to the discretion of.the.mechanist.
A,cylinder of two inches diameter and. three feet six inches long (for.example)
may be covered with six cutting bars, each a quarter of an inch thick; and
about one inch. and a quarter. broad on their upper surface, three of which,
that is, each alternate bar, may be removed when brought to a true. face as
.directed above, thus leaving a cylinder carrying three cutting blades; .but the
cylinder may be of any greater. length and diameter, and may be. mounted
with any greater number of cutting blades, so far as such length, diameter, and
number of blades do not render the manufacturing of the same impracticable,

page_text: or the operation of shearing the cloth less perfect. I have to state here tha
have found in practice that a good shearing angle will be formed if (
example) the cylinder on which the cutting blades are fastened-be two incl
in diameter and three feet six inches long, and the cutting blades a quarter
an inch thick (as above), if in such case each cutting blade in succession co
into action when the one immediately before it is censing to act, that is to s
each-cutting-blade-to-form-one-sixth-part of-an- entire revolution-in-the leng
of the said cylinder. And also that 'I have found it of advantage to have t
cutting edge of the said cutting bars ground in such a manner as not
coincide with radii of the cylinder, but to recede a little in its substan
below its upper surface, as represented ---
in the Drawing-hereto annexed;
where' A-is-the-eylinder, and B, one. .-
of the cutting- bars; C, its back- :
answering to a radius line; and -D,
its cutting edge: forming an -angle
with a radius line. And-further; I.
have to state that I have likewise.
found it of advantage to have a ring
half an inch broad (or more or less),
gist
and of the same: diameter as the
surface of the cutting blades, fastened
... ite
on: the leading end of the cylinder,
namely, that end at, which the cutting bars.begin to act, to prevent the cutti
bars as they successively come. into action from catching the corner of t
ledger, blade.. Respecting the advantages which accompany the use of
improved cutters, I need only mention their great durability, and the facil
with which they may be re-set when blunted, by merely taking them fro
their cylinder, and grinding their cutting edge D. And further, that ev
notches which they may meet with in hardening, in setting, or in working, w
not hinder them from performing their office, for the edge of the notch w
come into action with the ledger blade, almost instantly after the regular sou
part of the cutting edge. And this is truly the. case, that were, the whe
cutting edge in the form, of a saw, it would still perform its office; and ther
fore I claim as my Invention the solid cutting bar or bars before describe
fastened on a cylinder as above, whatever may be the form given to the cutti
edge.
In the foregoing description I have confined myself to that mode of structu
which I have found most advisable in practice, but skilful mechanists w

page_text: easily perceive that the construction may be varied, and yet present the same
or a similar form of cutting bars. Thus, for example, instead of fastening
cutting bars upon a cylinder as above directed, the cylinder itself, whether
solid or hollow, may be grooved in such a manner as to make portions of it's
own surface from the cutting bars; but although I have tried this method and
found it to answer, and claim it as a part of my Invention, yet I prefer the
method of making the cylinder above described and applying the cutters as
before mentioned, on account of the great facility it affords of removing the
cutters from the cylinder for the purpose of sharpening them.
To conclude, then, as my said Invention consists only in the improved make,
form, or structure of the said cutting bars, and does not embrace or require
any alteration in the ledger blade, or in any other part of the various machines
in use for shearing or cropping woollen cloth with rotary cutters, I have only
to add, that the revolving steel cutters of the improved form or construction
above described may be used as substitutes for the rotary cutters employed in
the machines in common use, whether patent or otherwise, and with any other
machines that may be constructed on similar principles.
In witness whereof, I, the said James Smith, have hereunto set my
hand and seal, this Seventeenth day of October, in the year of our Lord
One thousand eight hundred and twenty-one.
AND BE IT REMEMBERED, that on the same Seventeenth day of
October, in the year above mentioned, the aforesaid James Smith came before
our Lord the King in His Chancery, and acknowledged the Specification afore-
said, and all and every thing therein contained, in form above written. And
also the Specification aforesaid was stamped according to the tenor of the
Statute in that case made and provided.
T
J
Intahan in the moon shown written
ELZATTOO A