An Improved Instrument for Opening Sheet-metal Cans or Boxes.
Year: 1890

page_text: COMPLETE SPECIFICATION.
An Improved Instrument for Opening Sheet-metal Cans or Boxes.
We, THOMAS WILLIAM NEWEY and JOSEPH HENRY NEWEY, trading as Thomas
Newey & Sons, of Allison Street, Birmingham, Warwickshire, Joiners' Tool and Steel
Toy Manufacturers, 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 consists in the hereindescribed improved instrument for opening
sheet metal cans or boxes which said instrument is made in a peculiar form as herein
described and illustrated by the accompanying drawing whereby its efficiency is
considerably increased. The said instrument is illustrated on the accompanying
drawing in side elevation by Fig. 1; in front elevation by Fig. 2; in plan by Fig. 3;
in cross section by Fig. 4; and Figs. 5, 6 and 7 shew the said instrument in use.
The said instrument is one of that class of metal can or box openers which consist
of a pointed cutting blade A and purchase piece B fixed in a suitable handle C, and
this instrument is used in the ordinary way by first piercing the metal box or can
with the pointed end a of the blade A and then making upward and downward
strokes with the handle alternately about the front of the purchase piece B as a
fulcrum the instrument being moved forward after each upward stroke by which a
cut is made.
Our improved instrument for the purposes described has the cutting edge of the
blade A of the peculiar curved form shewn on the drawing so that the cutting edge
is all through the up stroke at about the same proper cutting angle with the surface
of the box or case which is being cut. This will be more clearly understood by an
examination of Figs. 5, 6 and 7 which represent three successive stages in a cut from
Fig. 5 where the upward stroke is just commencing to Fig. 7 where it is almost
completed. This curved shape of the blade A also enables the instrument to cut
cleanly and close to the edge of the top of a circular can or box so that the contents
can be more readily withdrawn than when the cut is jagged and some little distance
from the edge. It will also be seen that the curved shape of the cutting edge starts
from a point d very near to the front 6 of the purchase piece B. This enables the
cut to be made at one stroke almost to the point of contact of the front b with the
can or box. We prefer to bevel off that side only of the blade A which is away
from the side of the can or box when cutting round the top as this causes the blade
to keep and cut close to the side instead of its having a tendency to cut away
therefrom as is the case with some instruments for this purpose. The front b of the
purchase piece B is by preference notched or grooved so as to prevent its slipping
off or along the edge of the can or box when a cut is being made but we make no
exclusive claim to this point as we are aware that other can openers are made with
a notched purchase piece for this purpose.
Having now particularly described and ascertained the nature of our said inven-
tion, and in what manner the same is to be performed, we declare that what
we claim is :-
In an instrument for opening sheet metal cans and boxes and in combination
with the purchase piece B thereof (either notched at the end & or not) the employment
of the improved cutting blade A of the form substantially as hereinbefore described
and illustrated by the accompanying drawing.
Dated this 20th day of October 1890.
CHARLES BOSWORTH KETLEY,
Agent for the Applicants.