Improvements in Machines for Shearing Sheep.
Year: 1892

page_text: Date of Application, 5th Nov., 1892
Complete Specification Left, 5th Aug., 1893-Accepted, 4th Nov., 1893
PROVISIONAL SPECIFICATION.
Improvements in Machines for Shearing Sheep.
1, JOHN WALKER NEWALL, of Suffolk House, Laurence Pountney Hill, in
the City of London, Engineer, do hereby declare the nature of this invention to be
as follows:-
The cutters used in these machines have usually three teeth and in order to make
them cut evenly it is essential that an equal pressure be put on each tooth.
Springs are sometimes used for this purpose but they are unreliable.
In order to put a positive and equal pressure on each tooth I make use of two
sets of pivoted levers each set consisting of a lever with two arms which may
be equal or unequal in length, the pivots being formed one at each side of the main
axis of the vibrating lever.
If the cutter teeth are three in number then the arms of each pair of levers must
be in the proportion of two to one and both of the long arms of both pairs of levers
bear on the centre tooth of the cutter, and each short arm of each pair of levers
bears on one of the outer teeth of the cutter.
If the cutter has four teeth then each pair of levers has two equal arms and each
arm bears on a tooth.
This method may be applied to any kind of vibrating levers, whether they
adjust about the main pivot or have a loose cross-bar for adjustment or otherwise.
In the case of a loose cross-bar the levers are pivoted to the bar.
Dated this Fifth day of November 1892.
NEWNHAM BROWNE,
Agent for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Machines for Shearing Sheep.
1, JOHN WALKER NEWALL, of Suffolk House, Lawrence Pountney Hill, in the
City of London, 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:-
The cutters used. in these machines have usually three or four teeth and in
order to make them cut evenly it is essential that an equal pressure be put on
each tooth.
Springs are sometimes used for the purpose but they are unreliable.
In order to put a positive and equal pressure on each tooth I make use of two
sets of forks or pivoted levers each set consisting of a fork or lever with two
prongs or arms which may be equal or unequal in length according to the number
of teeth the pivots being formed one at each side of the main axis of the vibrating
lever.
If the cutter teeth are three in number then the arms of each fork or pair of
levers must be in the proportion of two to one as hereinafter shown and each long
arm of each pair of levers bears on the centre tooth of the cutter, and each short
arm of each pair of levers bears on one of the outer teeth of the cutter.
If the cutter has four teeth then each fork or pair of levers has two equal arms
and each arm bears on a tooth.
This method may be applied to any kind of vibrating levers whether they adjust
about the main pivot or have a loose cross head for adjustment or otherwise.
In the case of a loose cross head the levers are pivoted to the bar.

page_text: In the accompanying sheet of drawings
Figure 1 is a plan.
Figure 2 a side view of the front end of the vibrating lever of a shearing machine
showing my method of equalizing the pressure on the cutter.
Figure 3 is a plan of the same apparatus adapted to a four tooth cutter.
In Figure 1. 1 is a crosshead formed at the front end of the lever 2 which may
vibrate about an axis through the intersection of the cross lines at 3. Any of the
suitable known methods of pivoting or centring the lever may be employed and the
crosshead may be fast to or may swivel around the lever 2, and any suitable known
method of applying pressure to the lever may be employed, but it is essential that
either the crosshead or the whole lever be free to adjust itself so as to impart equal
pressure to the two pins 7 and 8 or their equivalents such pins being always equally
distant from the longitudinal axis of the lever. 4 is a cutter shown in Figure 1
as having 3 teeth but 4 teeth may also be used as shewn in Figure 3. 51 5' 5
and 5* are the arms or prongs of two pairs of compensating levers or forks pivoted
respectively around the pins 7 and 8.
In Figure 1. 5' and 5 each bear on one of the outside teeth of the cutter and 5'
and 5 both bear on the center tooth. The portions of each pair of levers about the
axes 7 and 8 are so arranged that the two inner arins are double the length of the two
outer ones and thus if pressure is applied to the axis of lever 1 it will be transmitted
in equal amount to each finger of the cutter.
In Figure 2. 6 represents one of the pins employed to drive the cutter.
If the cutter has four teeth as in Figure 3, then the arms of the compensating
levers must be equal and each one must bear on a separate tooth and the axes of
the compensating levers must be equally distant from the axis of the vibrating
lever and central respectively between the first and second and third and fourth,
fingers of the cutter.
Instead of the pins 7 and 8 any equivalent device may be used so long as the
levers are firmly held and yet free to swivel.
Having now particularly described and ascertained the nature of my inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. In a sheep shearing machine the construction and arrangement of pivoted
compensating levers carried by a main vibrating lever for producing an equal
pressure upon each tooth of a three or four toothed cutter during the clipping
substantially as described.
2. In a sheep shearing machine the use of a pair of pivoted levers of the shape
and construction shewn and described in combination with a main vibrating lever of
such a form that either the part of it that carries the pivoted levers or the whole
vibrating lever is free to turn about its longitudinal axis for producing an equal
pressure upon each tooth of a three or four toothed cutter during the clipping.
3. In a sheep shearing machine with cutters having three teeth the construction
and arrangement of a pair of pivotted levers having unequal arms carried by a main
lever whereby equal pressure is brought to bear on each tooth of the cutter
substantially as described and as shown in Figures 1 and 2.
4. In a sheep shearing machine with cutters having four teeth the construction
and arrangement of a pair of pivoted levers having equal arms carried by a main
lever whereby equal pressure is brought to bear on each tooth of the cutter
substantially as described and as shewn in Figures 2 and 3.
Dated the Fourth day of August One thousand eight hundred and ninety-
three.
JOHN WALKER NEWALL: