CERTAIN IMPROVEMENTS IN THE CON- STRUCTION OF INSTRUMENTS FOR SHEARING SHEEP OR OTHER ANIMALS."
Year: 1876

page_text: LETTERS PATENT to William Clark, of 232, Oxford Street, in the County of
Middlesex, for the Invention of "CERTAIN IMPROVEMENTS IN THE CON-
STRUCTION OF INSTRUMENTS FOR SHEARING SHEEP OR OTHER ANIMALS."
PROVISIONAL SPECIFICATION left by the said William Clark at the Office
of the Commissioners of Patents on the 13th September 1876.
WILLIAM CLARK, of 232, Oxford Street, in the County of Middlesex. "CERTAIN
IMPROVEMENTS IN THE CONSTRUCTION OF INSTRUMENTS FOR SHEARING SHEEP OR
OTHER ANIMALS"
The Invention relates more particularly to the construction of instruments to be
employed for shearing sheep, and is designed as a further improvement upon Letters
Patent granted to Arthur Dallison Renshaw, on the 19th of June 1866, No. 1645,
tho Specification of which describes amongst other things which tend to encumber
the machine a number of coarse teeth as the cutting medium similar in construction
and action to those of a reaping machine, the cutting plate of which has au
Oscillating movement from the centie upon which it is mounted, this too coarse
setting of the teeth has been found impractable, inasmuch that the skin of the
animal is liable with the pressure of the under plate upon its back required when
shearing to protrude into and get between the spaces of the teeth, and so become
damaged or cut. To remedy this and other obvious disadvantages which are set
forth in the herein-before recited Specification, and produce a machine or instru-
ment of a similar nature which shall be both simple and effective in its construction
and action is the object of this Invention.
The improvements may be thus described:-The lower or under plate or comb is
fixed to a handle by which the instrument is held and guided to its work similar to
that of Renshaw's, but in lieu of giving the reciprocating action to the cutting plate
by gearing I employ a lever handle which transmits a rectilinear motion to the
cutter plate in manner similar to machines now employed in clipping or shearing.
In all instruments of this kind hitherto used the cutting teeth have been mado
V shaped or nearly parallel like the teeth of a musical box in contradistinction to
which and according to the first part of these improvements I employ cutting teeth
which are in a great degree convex on the cutting edge somewhat after the shape of
an ash leaf.

page_text: In all previous machines of this class the action of the upper teeth when closing
upon substances gathored up between the lower teeth was direct and abrupt, the
severance of which was effected by a chopping or squeezing which left much to be
desired in respect both to the quantity cut, the amount of labour required, and the
cleanness of the cut effected.
By the use of my improved construction of teeth these faults are avoided and
perfection of cut obtained with the smallest possible amount of labour, as the
gradual contact of the cutting surface beginning from near the heel of the sharp
blade tooth or shear, and proceeding in a gentle curve fully towards the points of
the same performs in the most efficient manner the true shear-like cut as
distinguished from the chop or sudden jarring action, which requires greater force
and renders the machine more liable to get out of order.
The second part of my improvement relates to the application to the handle or
handles of such machines of a coiled or spiral spring similar to that of a watch
having one of its ends fastened to the fulcrum pin or axle attached to the lower
handle and lower plate, and the other end fastened to a pin inside a cap which
forms part of the upper or movable handle or in other words one end of such
spring is fixed to a stationary part of the instrument and the other to the movable
handle, the whole being covered by a cap or otherwise. A great advantage derived
from the use of this or similar springs is that the movable handle is actuated so as
to give a soft spring-like motion, and procuring a return or back cut by means of the
said spring. If desirable other forms of springs may be employed for this purpose,
such as that described in the Specification of Letters Patent granted to me on the
7th day of July 1874, No. 2373, or modifications thereof.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said William Clark in the Great Seal Patent Office on the 13th March
1877.
WILLIAM CLARK, of 232, Oxford Street, in the County of Middlesex. " CERTAIN
IMPROVEMENTS IN THE CONSTRUCTION OF INSTRUMENTS FOR SHEARING SHEEP OR
OTHER ANIMALS."
The Invention relates to that description of shearing instrument in which an
upper plate provided with a series of cutting teeth is caused to reciprocate or
oscillate over the teeth of an under comb or plate, the action of which when applied
to the back of an animal clips or shears therefrom according to the nature of produce
wool, hair, or other substance gathered by the under comb.
Firstly. The Invention relates to the cutting teeth of the upper plate, and
consists in making the cutting edges of the same convex or curved.
Secondly. The Invention relates to an arrangement of parts designed for
governing and adjusting the pressure on and movement of the top cutter plate.
Thirdly. The Invention relates to an adaptation to the said cutter plates of an
arrangement of framing and gearing which will enable the instrument to be driven
by power.
In order that the Invention may be well understood and explained in detail,
I have hereunto annexed a Sheet of Drawings made about full size upon which
letters of reference are marked on corresponding parts on all the Figures alike.

page_text: arrangement of applying to the instrument a coiled spring, the purpose and object
of which is to automatically open the working handles giving motion to the cutter
plate after the same have been closed by pressure.
Fig. 3 represents a side elevation of the same, and Fig. 4 is a similar view
shewing the arrangement of a top pressure plate without the addition of a coiled
spring, which said pressure plate is a modification of the pressure fingers shewn at
Fig. 5, such said pressure fingers being the subject of a Patent granted to me in
1873, No. 1228, in this view is also shewn the application of a coiled spring between
the handles, the use of which is to force them apart.
Fig 6 represents a section of the cutter plates shewing the position and arrange-
ment of the spring fingers and studs for adjusting the pressure and determining the
throw of the cutter plate.
Fig. 7 represents a similar section to the last, in which a rigid finger and set
screw are employed for the purposes before mentioned.
Fig. 8 represents a two hand clipper of the construction ordinarily employed for
clipping horses, the top cutting teeth of which are of a pattern similar to those
forming the subject of the first portion of these improvements.
Figs. 9 and 10 represent in plan and side elevation, a shearing instrument in
which the cutter plate has an oscillatory motion, and Figs. 11 and 12 represent
similar views to the last, in which an adjustable spring plate is employed for
adjusting the pressure between the surfaces of the cutting plates, such spring being
a modification of the spring washers described and shown in the Specification of the
Patent of 1873, herein-before referred to.
Fig. 13 represents an arrangement of parts for giving motion to the cutter plate
through the medium of rack gear.
Fig. 14 represents the peculiar formation of open connection which I prefer to
adopt for blade springs when applied, as shewn at Fig. 9, for automatically opening
the handles of clipping or shearing instruments, such opon connections being a
modification of the closed hinge shewn at Fig. 14ª.
Fig. 15 represents a construction of cutter plate in which the slot determining
the rectilinear motion of same through the medium of abutting studs fixed in the
bottom plate is placed below the throw pin.
Figs. 16, 17, and 18 represent two clippers or shearing instruments of the
description herein-before mentioned in so far as relates to the cutting teeth and
plates, but in which such cutters are actuated to shear by power instead of by hand.
On reference to the Figures above described it will be seen that the top cutter
plate B is provided with teeth, the cutting edges of which have a convex formation
shewn enlarged at Fig. 1, and are made of a fine or coarse pitch to work in con-
nection with an under plate or comb. A having teeth of any desired pitch or number
according to the substance the cutters are intended to operate upon The action of
these convex edges sever with an even clean cut the material gathered by the under
comb without the slightest tendency to chop, as the gradual contact of the cutting
edges beginning near the root 1 proceeds to sever the substance from thence with
a gentle curved edge up to the points 2, the result being a perfect easy shear like cut
as distinguished from the chop or jar experienced when shearing with angular or
parallel teeth.
The second part of these improvements is designed as a further development of the
Patent of 1873, herein-before referred to, and in which pressure fingers in connection
with screw nuts and stems fixed in and projecting from the bottom plate were
employed as the medium for adjusting and maintaining the "set up" or pressure
between the cutting surfaces of the shearing plates.
According to my present improvements I employ similar yielding fingers a, a
seen at Figs. 5 and 6, or a top pressure plate a, a, as seen at Figs. 2 and 3, but'
in lieu of fixed stems projecting from the bottom plate A and screw nuts and
washers, I provide the ends of the fingers a, a, with studs c, c, as seen at Fig. 6,
which project through the washers b, b, and enter the slots of the cutter plate B, in
which position (when the fingers a, a, are fixed) they form guides which govern the

page_text: rectilinear movement of the plate B, the adjustment and maintenance of pressure
being obtained in manner similar to that described in the Specification of the
Patent herein-before recited
In Fig. 7 a modification of the yielding fingers a, a, of Fig. 6 is shewn in this
arrangement; the fingers a³, a³, are made rigid and provided with set screws which
enter recesses in the washers; the under surfaces of these washers form studs o
which enter the slots of the plate B; thus when the set screws d are screwed down
they exert a pressure upon the washers b, which not only adjusts the pressuro
between the plate A and B, but also through the medium of the washer studs c
retain the plate B in its sliding rectilinear position.
A further modification of these pressure fingers is shewn at Figs. 2 and 3, in
which is substituted therefor the top plate a¹ which is fixed and arranged to exert
a pressure only on the roots of the teeth of the cutter plate B, the adjustment of
such pressure being regulated by the stems, nuts, and washers g. The coiled
springs shewn as applied to the fulcrum stud v in Fig. 1 to press upon the throw
pin or on a pin w fixed in the working handle, or if placed between the handles of
the clipper, as seen in Fig 5 is adapted for the purpose of giving the operator the
power of clipping or shearing with the right or left hand or with both, as after
each closing of the handles by hand they are caused to open by the action of the
spring 8. I am aware that springs in connection with clippers have hitherto been
used which would enable the operator to clip with one hand, but not the novel
forms of coiled springs here shewn, as added to the advantages of economy and
adaptability, they when in action yield gently to the pressure of the hand when
closing, and when released recover themselves in a manner which gives a supple
easy action to the cutters without jump.
י
In Figs 9, 10, 11, and 12, my present improvements are shewn in connection
with clippers whose cutters have an oscillatory movement or throw. According to
this arrangement, as seen in Figs 9 and 10, I dispense with the pressure
fingers a, a, and substitute therefor a top plate a², which forms a prolongation of
the working handle f, this plate a is fan-shaped and so constructed that its
segmental extremity will bear uniformly on the cutter plate; near the roots of the
teeth the adjustment of pressure given by this plate to the cutting surfaces of the
teeth is obtained by means of the nut c, spring washer e¹, and fulcrum stud f, the
tightening down of the nute on the fulcrum stud f enables the operator through
the medium of the spring washer e¹ to adjust the pressure between the cutting
surfaces of the teeth with the greatest nicety, or the spring medium may be a
coiled spring interposed between the washer e² and the plate B, or a transverse
spring finger e, as seen at Figs 11 and 12 The throw or movement of the cutter
plate in Fig. 9 is transmitted from the working handle through the stud i projecting
from the plate behind the fulcrum, the throw being determined by the abutting
studs o.
At Figs. 16, 17, and 18, the cutting plates A and B are shown as adapted to an
arrangement of apparatus which enable them to be driven by power The arrange-
ment shewn at Figs. 16 and 17 consists of a driving pulley h, cam i, and lever k,
the whole being supported by the frame 1, the power being transmitted from a
driving shaft and pulley through an endless elastic driving cord; or as an
equivalent for this class of driving I employ an arrangement of apparatus shewn at
Fig. 18, in which a flexible rotating driving cord m is coupled to the spindle n
terminating in a crank disc o, the crank pin of which gives motion to the working
lever p, and so transmits a vibratory motion to the cutter plate B.
In these descriptions of power machines I adapt to the upper framing a handle
which in conjunction with the rear handle enables the operator to regulate the
pressure of the cutting plate A on the skin of the animal, and at the same time
guide the cut in any direction required with ease and facility.
I would remark that in the arrangement of driving shewn at Fig. 16 and 17, the
pulley / may be withdrawn and the spindle of the cam i be coupled direct with a
flexible rotating cord similar to that shewn at m, Fig. 18,

page_text: Having now described the nature of my said Invention, together with the
method of carrying the same into practical effect, I would wish it to be distinctly
understood in conclusion that I claim,—
First The novel form of convex cutting edges as applied to the teeth of the top
cutter plate of clipping and shearing instruments.
also
Second. The terminating studs c of the fingers a, a, shewn at Figs. 5 and 6;
the rigid fingers a³, set screws d, and washers c, shewn at Fig. 7; also the sub-
stitution of the top plate a¹ for the fingers a of Figs. 5 and 6, the whole of which
are to be used for the purpose and in the manner substantially described.
Third. The novel adaptation, employment, and use of coiled springs in con-
nection with clipping or shearing instruinents, as shewn at Figs. 2 and 5, or of flat
blade springs connected when at work, as shewn at Figs 9 and 14, or any slight
modification of the same when used substantially as in the manner and for the
purpose described.
And, lastly. I claim the general and separate employment, use, and combination
of the several parts referred to in the various Figures or any slight modification of
the same when used substantially in the manner and for the purpose described and
set forth in the Drawings annexed.
In witness whereof, I, the said William Clark, have hereunto set my hand and
seal, this Fifteenth day of February, in the year of our Lord One thousand
eight hundred and seventy-seven.
WILLIAM CLARK. (LS.)