AN IMPROVED IMPLEMENT FOR OPENING SHEET METAL CANS, CASES, OR BOXES
Year: 1875

page_text: PROVISIONAL SPECIFICATION left by Arthur Helwig and Perkins
Eugene Cox at the Office of the Commissioners of Patents, with
their Petition, on the 22nd December 1875.
We, ARTHUR HELWIG, of Gloucester Road, in the County of
Middlesex, Engineer, and PERKINS EUGENE Cox, of Hunter Street,
Brunswick Square, in the County aforesaid, Gentleman, do hereby
déclare the nature of the said Invention for "AN IMPROVED IMPLEMENT FOR
OPENING SHEET METAL CANS, CASES, OR BOXES," to be as follows:―
Our Invention relates to a novel implement or apparatus for cutting
open sheet metal cans, cases, and boxes, such as are used for condensed
milk, preserved meat, fish, fruit, and vegetables, and other thin metal
cans or enclosures, which are sealed or closed by solder or the like, and
have to be opened by cutting the metal of which they are formed.
Various implements or apparatus have been devised for this purpose,
but none of them have been found thoroughly efficient, and none have
yet been produced whereby the cutting or opening of these cams, cases,
or boxes can be effected without great exertion, soiling the hands,
danger of cutting the fingers by the rough and jagged edges left by the
.!»,

page_text: cutting and other inconveniences. But by our Invention we produce an
implement which is free from these objections, and which affords the
means whereby sealed sheet metal cans, cases, or boxes, may be readily,
conveniently, and safely opened by any person capable of using an
ordinary knife or similar implement.
Our improved implement is chiefly designed for cutting off the ends of
circular cans or "tins" as they are sometimes called, and consists
essentially of a lever or plate properly shaped to be grasped by the hand
provided with a knife or cutter, and formed with two abutments or
bearing pieces arranged relatively at such an angle to the said knife or
cutter, that when the implement is so placed upon a can or "tin" as to
grasp the end or head of the same between the said abutments, and the
edge of the knife, and the implement is turned round thereon with
pressure upon the knife, the latter will cut through the metal and
separate the end from the "tin" with very slight exertion.
The lever or plate of the said implement is preferably formed of cast
malleable iron. The two abutments or bearing pieces are cast upon the
said plate or lever, at a distance apart equal to about one-sixth of the
circumference of the cans to be opened thereby. These two abutments
are so arranged that one is farther than the other from the edge of the
knife, the result of this peculiar arrangement being to prevent the
slipping of the implement from the can, and to cause the knife to
penetrate the metal when the implement is turned upon the end of the
can. The knife which we use in our improved implement is a small
steel disc with a cutting edge all around the same. This disc is fitted to
turn upon a pin fixed in a sliding block working in a slot, a pivoted
lever, or other adjustable piece, which will permit the cutter to be set
nearer to or farther from the said abutments. We prefer that the said
adjusting piece should be a lever pressed up by a spring, so that the
pressure necessary for causing the penetration of the metal by the knife
may be obtained automatically; but we may sometimes use a screw
attached to or formed on the end of a handle fitted to turn in one end of
the said lever or plate, the implement being turned and the pressure
applied to the cutter by this handle. But we prefer to use a short lever
pivoted at one end to the metal plate and carrying the cutter on its other
end, which is pressed inward by the spring, and to dispense with the
said handle and form the plate itself to be conveniently grasped and
turned upon the can while the required pressure is exerted upon the

page_text: knife by the spring. The said adjustable block or lever may be provided
with two or more openings for the reception of the knife or cutter, so
that the same may be set to cut more or less from the end of the can as
may be required.
To adapt our improved implement to the opening of square or rect-
angular boxes, or cases, we provide the same with a fixed blade or cutter
at the outer edge of one of the said abutments, the said blade being so
formed and arranged that by inserting its point through the metal of the
case or box, and properly manipulating the implement, the said case or
box may be conveniently and quickly opened.