Improvements in Shears for Cutting Sheet Metal.
Year: 1894

page_text: Date of Application, 9th May, 1894
Complete Specification Left, 11th Feb., 1895-Accepted, 9th May, 1895
PROVISIONAL SPECIFICATION.
Improvements in Shears for Cutting Sheet Metal.
I JAMES WATT of 37 Summerfield Terrace, Aberdeen, Scotland, Blacksmith,
do hereby declare the nature of this invention to be as follows:-
This invention is designed so that both handles of the shears are above the sheet
when cutting which greatly facilitates this operation and also allows the sheet to
pass the side of joint without hindrance.
According to this invention the lower jaw is made with a straight cutting edge
from point to heel and the jointed parts are kneed back exactly at the height of the
cutting edge and to a distance of about equal to the thickness of the jaw so as to
allow the sheet when cut to pass along the side of the joint without the least
hindrance.
The upper jaw is made similar to the lower one and the joint of it is also kneed
back so as to allow it to pass the back of the joint of lower jaw, the upper jaw is so
adjusted to the lower one that when the shears are closed the points at the cutting
edges are exactly level while the heel of the upper cutting edge has passed down
low enough to be first level with the bottom side of the knee. This allows the
sheet while being cut to be pushed down just clear of the knee and thus pass out
behind the shears quite easily.
This invention is also applicable to machine shears worked by steam or other
motive power.
I JAMES WATT, of 37 Summerfield Terrace, Aberdeen, Scotland, Blacksmith,
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 :-
This invention is designed so as to allow the handles of shears to pass over a
sheet of metal, whilst being cut, and also to allow of the edges of the metal passing
on either side of the joint without hindrance, so as to facilitate the operation of
cutting.
According to this invention the lower jaw of the shears is made with a straight
cutting edge, from point to heel, and the jointed parts are kneed back on one side
exactly at the height of the cutting edge, and to a distance about equal to the
thickness of the jaw: so as to allow the sheet when cut to pass along the sides of
the joint, without the least hindrance.
The joint of the upper jaw is also kneed back, so as to allow it to pass the back
of the joint of the lower jaw.
This invention is also applicable to machine shears, worked by steam or other
motive power.

page_text: And in order that my said invention may be better understood, I will now
proceed to describe the same with reference to the sheets of drawings accompanying
this Specification, in which Fig. 3. shews front elevation, and Fig. 4 a plan of
under side of a pair of hand shears constructed according to my invention: Fig. 1
an end elevation, and Fig. 2 a partly sectional front elevation of my improvements
as adapted to machine shears.
In Figs. 3 and 4 the same letters denote the same parts, as also in Figs. 1 and 2.
With reference to Figs. 3 and 4, L shews lower jaw, J upper jaw, N N shew
where these jaws are kneed back: S shews a sheet of metal, as it would appear
when being cut, S¹ S² the edges of the divided metal passing out at the back,
K shews joint of the two jaws, the head of the pin securing said joint is cut away,
as at Z, to allow of the sheet of metal passing freely under such head whilst being
cut H H shew the handles, which are bent so as to come above the sheet S
when in use.
With reference to Figs. 1 and 2 shewing my improvements as adapted to machine
shears A shews the frame-work, P P represent fast and loose pulleys, S shews the
driving spur pinion, W the spur wheel, keyed to the disc shaft B, D disc driven in
a right direction, is a link, connecting the disc D and the rocking plate R, as
shewn at Figure 1. J shews the upper cutting jaw, screwed on to the rocking plate R,
L shews lower cutting jaw which is fitted in a dove-tail in the frame A, as shewn
at F, K, shews the joint, the head of the pin of which is cut away, as above
described, with reference to Figs. 3, and 4.
The action is as follows:-
The sheet of metal to be cut, is put between the upper and lower jaws, either in
the hand or machine shears, as the case may be, and upon the shears being actuated,
it will be seen (on reference to Fig. 3 at S¹ and S² for hand shears) that the two
edges of the cut metal pass freely on either side of the jaws in both the hand and
machine shears on account of the head Z of the joint pin being cut away as shewn.
On reference to Fig. 3 it will be seen, in the case of hand shears, that the
handles H H are bent so as to pass over the surface of the sheet during cutting,
by which means a length of metal extending beyond the handles may be cut
without having to bend the sheet down, as in the case of shears made in the
ordinary way.
Fig. 5 shews section through line ab Fig. 3.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is:-
1. Constructing hand and machine shears substantially as hereinbefore described
and represented on the accompanying sheets of drawings.
2. Hand and machine shears constructed with kneed joints for the purpose
set forth.
3. In hand shears the handles being bent in such a way that they may pass
above the sheet of metal during cutting substantially as hereinbefore described and
represented on the accompanying sheet of drawings at Fig. 3.
BROWNE & Co.,
9, Warwick Court, Gray's Inn, London, W.C.