Improved Means of Regulating the Tension of "Double Bow Sheep Shears.
Year: 1889

page_text: COMPLETE SPECIFICATION.
Improved Means of Regulating the Tension of "Double Bow
Sheep Shears.
19
I, REUBEN WITHELL, of Brookside. Canterbury. New Zealand, Sheep Farmer, 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:
My improvements in the construction of sheep shears relate more particularly to a
regulator for "double bow" sheep shears, whereby the tension of the bow may ho
quickly adjusted to suit the hand of the shearer and the class of wool to be operated
upon. This regulator is applicable to all "double bow sheep shears where the two
ends of the bows are brought together and form a central "tongue" between the
bows.
Such "double bow" shears have heretofore been made with a slot in the "tongue"
to receive an adjustable bolt whereby to regulate the tension, but, according to my
invention, the "tongue" is made in two equal parts by extending the slot to the
terminal end of the said "tongue" and, in lieu of the ordinary bolt and nut by which
the tongue is gripped only near the centre of its width, a regulator, composed of two
"at or near
cross-bars connected by a thumb-screw and adapted to grip the "tongue
its extreme side edges, is provided, as hereinafter described with reference to the
drawings wherein figure 1 is a view of the bows of a pair of shears, shewing the
"tongue" in two parts. Figure 2 is a similar view shewing the regulator applied
thereto. Figuro is a cross-section of the "tongue" shewing the cross bars and
thumb screw full size.
The "tongue" of the bows is made in two equal parts A A, figure 1, which are
open to the head of the bow B an equal width of three-eighths of an inch, the terminal
ends of these parts are secured by rivets a a or equivalent means. The tension
regulator consists of two cross-bars (placed one on each side of the "tongue" at
right angles to the slot b and connected by a thumb-screw c which passes freely
through the one bar and through the slot and screws into a tapped hole in the other
bar. Those two bars correspond in length to the width of the "tongue" A A and
their inner or pressing faces are so shaped or shouldered that their gripping pressure
will be wholly applied to the tongue as near as possible to the side edges d d
thereof, thus preventing what is called "buckling" and also preventing lateral
deflection of, and mutual injury to, the blades which is liable to happen when the
regulator grips the "tongue" in the centre of its width only.
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By adjusting the regulator near the head of the bow B, the tension or stiffness of
the spring is increased and by moving it towards e, as shown in figure 2, it is decreased
and a soft and easy motion is obtained, one pair of shears being thus made suitable for
any class of wool
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, I declare that what I
claim is;
1. Making the "tongue" of "double bow" sheep shears of two equal parts A A
having a slot or opening b extending to the terminal end of the said tongue,"

page_text: 32
2. The hereindescribed means of regulating the tension of the bows, consisting of
the cross-bars (connected by a thumb-screw e and adapted to grip the "tongue
near its outer edges, substantially as hereinbefore described and illustrated in the
accompanying drawings.
Dated this 7th day of November 1880
R. WITHELL.
By A. M. & Wm. Clark,
53, Chancery Lane, London, Patent Agents.