Improvements in Cutters for Opening Tin Canisters and the like.
Year: 1899

page_text: Date of Application, 18th May, 1899
1000 Accepted, 14th Apr., 1900
PROVISIONAL SPECIFIO
Improvements in Cutters for Opening Tin Canisters and the like.
I, FREDERIC WELDON DAW, of Eureka Place, Ebbw Vale, Monmouthshire,
Photographer, do hereby declare the nature of this invention to be as follows:-
My invention relates to improvements in the opening of sealed tin plate
canisters. It is especially applicable to canisters containing substances of which
it is desirable to preserve the moisture or the aroma by hermetically sealing the
canister, whilst at the same time providing a convenient and simple method of
opening the same whenever desired. Such canisters are largely used for contain-.
ing. tobacco, cigarettes, and so forth, and the construction specially adapted for
this purpose is that in which the canister is provided with a double lid or head,
cf which the upper lid fits, in the usual manner, upon the cylindrical end of the
canister and is merely secured in place by the label pasted over it, whilst the
hermetical sealing is effected by an inner head of suitable thin plate, secured
airtight at a short distance beneath the upper lid. These canisters are well-
known, and devices have been invented and patented for conveniently opening
them by simply rotating the upper lid which for this purpose has a sharp cutter
or point attached to its under surface and placed at a point near the periphery
of the said lid. This cutter, projecting vertically downwards, penetrates the thin
inner lid and when the upper lid is rotated makes a circular incision around
the said inner lid thereby detaching nearly the whole of the said inner lid in
the form of a circular plate. The practical drawback which renders this device
less convenient and suitable than it otherwise would be is that this vertical cutter
as at present applied produces a sharp and sometimes jagged edge of cut plate,
which edge is left projecting all round the inside of the tin and frequently causes
injury to the hand of the user when removing the contents of the tin. My inven
5 tion is designed to obviate this drawback. In place of a straight cutter projecting
vertically downwards as hitherto I provide a cutter the cutting portion whereof
is bent obliquely to the radius of the circle of the cover and also obliquely to
the plane of the lid to be cut. The blade of the cutter is also preferably slightly
curved. By this alteration in the shape and setting of the cutting blade I obtain
30 an incision in which the edge of the ring left by the cut plate is turned over so
as to present a rounded surface to the inside of the tin and consequently any
chance of injury to the materials or the hand of the user is avoided. It is
immaterial for the purposes of my invention whether the cutter be arranged to
turn over the edge aforesaid in an upward or a downward direction, but for most
35 purposes I find it preferable in practice to turn over the edge downwards. It
will be obvious that my improved method and apparatus for cutting and turning
in the edges of these inner lids may be modified in various constructional details
ovice may be combined with other already known constructions or may

page_text: be made adjustable radially or otherwise according to requirements, such detail
modifications will not however remove the device from within the scope of my
invention.
Dal 1
1011 1
exc
1000
W. P. THOMPSON & Co.,
322, High Holborn, London, W.C., Patent Agents.
I, FREDERIC WELDON DAW, of Eureka Place, Ebbw Vale, Monmouthshire,
Photographer, 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 invention relates to cutters for opening tin canisters and the like. It is
especially applicable to canisters containing substances of which it is desirable
to preserve the moisture, or aroma, by hermetically sealing the canister, whilst
at the same time, providing a convenient and simple method of opening the
canister when desired. Such canisters are largely used for containing materials
such for example as tobacco, cigarettes, and the like, and the construction specially
adapted for this purpose is one in which a head of thin plate usually called
"tagger plate" is used for closing the canister air-tightly, a lid being fitted over
this upon the end of the canister and usually secured in place by a label pasted
around it. These canisters are wellknown, and devices have been invented and
patented for opening them by rotating the upper lid which for this purpose a
cutter is provided attached or attachable to its under-side and placed at a point
near the periphery of the said lid and projecting vertically downwards so that it
can be caused to penetrate the tagger plate and, when the upper lid is rotated
to make a circular incision around the said tagger plate and thereby detach it
so as to allow of access to the contents of the canister. The practical drawback
which renders this device less convenient and suitable than it otherwise would be,
is, that the vertical cutter as at present applied produces a sharp, and sometimes
jagged, edge of cut plate, which edge is left projecting all round the inside of
the canister and frequently causes injury to the hand of the user when removing
the contents of the canister. My invention is designed to obviate this drawback.
Figure 1 of the accompanying drawing shews in transverse section and Figure 2
in plan of underside a lid for a canister provided with a cutter having the cutting
portion formed according to my invention, Figure 3 shews the said cutter
separately drawn to a larger scale. The lid is marked A and the cutter B. In
place of a straight cutting portion projecting vertically downwards, as hitherto, I
provide a cutter the cutting portion b whereof is bent obliquely to a radius of the
circle of the cover and also obliquely to the plane of the lid to be cut. The blade
of the cutter is also preferably slightly curved as shewn in Figure 3. By this
shaping and setting the cutting portion, I obtain an incision in which the edge
of the ring, left by the cut out tagger plate, is turned over so as to present a
rounded surface to the inside of the tin and consequently any chance of injury
to the materials, or to the hand of the user, is avoided. It is immaterial for the
purposes of my invention whether the cutter be arranged to turn over the edge
aforesaid in an upward, or in a downward, direction, but, for most purposes, I
find it preferable in practice to turn over the edge downwards. It will be obvious
that my improved cutter for cutting and turning in the edges of the tagger may
be arranged in various ways in connection with the lid for instance it may be

page_text: arranged to slide radially by bending over portions at the side to engage sto
in the lid, or it may be made so that it can be placed between the tagger plate
and the lid and secured to the lid for use or be otherwise arranged according to
requirements as is usual with the cutters hitherto used without departing from
the nature of my invention.
Having now particularly described and ascertained the nature of my invention
and in what manner the same is to be performed, I declare that what I claim is:-
A cutter for opening tin canisters and the like, the said cutter having the
cutting portion arranged obliquely to a radius of the circle of the cover, and
obliquely to the plane of the plate to be cut, substantially as hereinbefore
described.
1900
JOHNSONS & WILLCOX,
47 Lincoln's Inn Fields, London, W.C., Agents.