Improvements relating to Machines for Shearing Sheep and other Animals.
Year: 1898

page_text: Date of Application, 27th Dec., 1898-Accepted, 4th Nov., 1899
[Communicated from abroad by ROBERT DANGAR DIXON, of 25, Elizabeth Street,
Sydney, New South Wales.]
Improvements relating to Machines for Shearing Sheep and other
Animals.
I, PHILIP ARTHUR NEWTON, of The Office for Patents, 6, Bream's Buildings,
Chancery Lane, in the County of London, Patent Agent, 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.-
Hitherto, owing to the way in which the combs and cutters of machine sheep
shears have been made and ground, the cut that they effect has not been a true
cut, but has been merely a breaking of the fibre by percussion
In order that the
percussive action of the cutter upon the fibie may be effective, it has been found
necessary to dive the machines at a very high iate of speed, and this, together
with the excessive tension that is required to bo applied to the cutter, necessitates
a much higher degree of power to dive the machines than should be necessary
were the cut a true cut.
This invention has been specially devised with a view to obtain a true cut of
the fibie, by causing the cutting edges of the cutter to work along the cutting
edges of the comb, in the same way as the two cutting edges of a pair of scissors
or a pair of hand shears work together
In the accompanying drawings, Fig 1, 16 a plan of the sheep sheal, the cover
being laid open
Fig. 2, 18 a longitudinal vortical section of the same taken through the central
longitudinal axis of the machine.
Fig. 3, 18 an underneath plan of part of the main actuating lever and the
tension spring.
Fig. 4, is a front elevation of the comb and cutter, shewing the tension bar.
Fig 5, 18 a section through the comb shewing the action of the cutter with the
comb.
Figs. 6, shew several alternative modes of making the cutter, whereby the
BC1ssor cut may be effected
A is the central axial pin, which also serves as a tension screw Bis the main
actuating lever, forked at its rear end to receive the anti-friction 1oller c of the
diving disc C, which 18 caused to rotate by any suitable means Below the
leve B 18 vetted the tension spring D, the forward end of which 18 foihed as
at ỉ so as to allow of the passage of the axial pin A The forked part d of the
sping D 18 inserted into a stop socket e which is boned to permit of the passage
of the pin A, the upper end of which is threaded to receive the tension nut F,
which, when it is screwed down tight, will be retained in that position through
the instrumentality of a stop upon the spring f, which will engage with one of
the peripheral notches in the nut F, in a manner well known and understood
The forward end of the lever B is shaped like a fork with thee prongs, b, b, ba,
the two outside prongs b-, being provided underneath with studs d', d, which

page_text: engage with corresponding recesses in the cutter G. It is by means of the
studs d, d, that the reciprocatory movement of the lever B is communicated to
the cutter G. The cutter G 18 of the two pronged type as may be seen by
iefening to Figs 1, 4 & 6. Bearing down upon the cutter G is the tension bar H,
which is pivotted to the central piong b¹ by the screw h. By means of this
tension bai H the tension is evenly distributed upon the two teeth of the cutter.
The comb J 18 preferably ground perfectly flat on its upper side, but it may be
made concave, in the form of a segment of a cylinder, for reasons to be hereafter
explained The under side of the cutter G 18 hollow ground, in the form of a
segment of a cylinder, as shewn in Fig. 5 and the Fig of Figs. 6
The cuive
has been exaggerated, in the drawing, to render it more apparent. By gunding
the cutter hollow, or segmentally cylindrical, the result will be that the points
of its teeth will drop equally into the spaces between the teeth of the comb,
and the cutting edges of the cutter tooth will giind against the cutting edges of
the comb teeth, thus producing a true cut or shear on anything that is placed
between. The effect is precisely similar to the shearing effect produced by the
two blades of a pan of scissors or shears while they are in process of being closed
together Instead of hollow grinding the cutter as shewn at a Fig 6, a very
similar effect may be produced by slightly raising the heel of the cutter upon
studs y (Fig 6, y, z), or upon a thin stip of metal z³ (Fig. 6, 2, 2¹), or the cutter
may be flat ground and the comb hollow ground on its upper sui face Either
of these methods would produce the same effect, uz:-that of depressing the
points of the teeth of the cutter equally into the spaces between the teeth of the
comb, resulting in a shearing action between the cutting edges of the teeth of
the cutter and the comb
But the shearing action would not eventuate if the teeth of the comb were
made parallel to one another as is generally the case It has therefore been
found necessary to construct the teeth of the comb and of the cutter, on lines
radiating from the centre of the axial pin A When the cutter reciprocates to
and fio, it will always be parallel with the comb, and the shear or cut will always
be the same, no matter at what part of the comb the cut takes place.
Owing to the dip of the points of the teeth of the cutter into the spaces between
the teeth of the comb, the traverse of the cutter would necessarily be somewhat
undulatory, which, but for the special devices employed, could not fail to
materially affect the efficiency of the tension. Refering to Fig. 2, it will be
seen that the spring D would have a tendency to elevate the rear end of the
lever B and thereby to depress the fork b, b¹, 6, at the forward end of the same,
and, if the cutter were rigidly secured to the forks, the tension could not be
evenly distributed over the cutter This objection is obviated by the tension
bar H, which is articulated to the central fork 61 by the screw h, so as to be
susceptible of movement only in a plane at right angles to the plane of move-
ment of the lever, and therefore, no matter what may be the position of the
lever B, the tension will always be evenly distributed over the cutter.
In order that the concavity of the cutter or the comb should be rendered
thoroughly effective, it will be necessary that the tool should be ground upon the
periphery of a cylinder in a similar manner to that adopted in grinding edge
tools upon a grinding wheel, but the teeth must lie in planes as nearly as
possible parallel to the plane in which the wheel is revolving The underside
of the cutter, when thus ground, will assume the form of a segment of a cylinder,
the concavity being equal to the convexity of that portion of the grinding wheel
which can be covered by the cutter.
It is obvious that the principle of the hollow ground cutter may be applied
with equal facility to horse-clippers and other appliances of an analogous type
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, (as communicated
to me from abroad), I declare that what I claim is:-
-
1. In machine sheep-shears, so constructing the cutter or the comb, that the

page_text: teeth of the cutter shall be caused to dip equally into the spaces between the
teeth of the comb, and thus bring the cutting edges of the cutter and of the comb
into actual contact, as and for the purposes herein set forth.
2. In machine sheep-shcais, a cutter the under surface of which is concave,
ground into the form of a segment of a cylinder, whereby the teoth of the
cutter shall be caused to dip equally into the spaces between the teeth of the
comb as herein described
3. In machine sheep-shears, 1aising the heel of the cutter by means of studs or
a thin plate, whereby the teeth of the cutter shall be caused to dip equally into
the spaces between the teeth of the comb as specified
4 In machine sheepshears, a comb, the teeth of which are constructed on lines
radiating from the axial pin of the main lever, in combination with a cutter
the teeth of which are also radial, such cutter being either hollow ground on its
under surface or so constructed that its teeth shall be caused to dip equally into
the spaces between the teeth of the comb, as and for the purposes specified
5. In machine sheep shears, in combination, a reciprocating lever, a cutter
with two teeth working over a comb, and a tension bai which is articulated to
the centre of the forward edge of the reciprocating lever in such a manner that
it shall be susceptible of movement only in a plane at night angles to the plane of
the movement of the lever, each end of such tension bar resting upon the base
of one of the teeth of the cutter, for the purpose of distributing and equalizing
the tension on the cutter as specified
6. In machine sheep shears, the reciprocating main lever, in combination with
the tension sping, which 18 11vetted to the lever towards its ical end, while the
forward end of the spring is bent downwards and forked so as to embrace the axial
pin of the main lever at a point near the lower side of the casing where it is
enclosed by a stepsocket such as c Fig. 2, whereby the rear end of the main lever
is raised and its forward end depressed upon the tension bar in front, as specified.
7 The general arrangement, construction and combination of parts in my
Scissor cutting machine-sheep-shear, as and for the several purposes herein
specified