A Weighing Device Applicable to Pocket-knives and the like.
Year: 1890

page_text: Date of Application, 9th Apr., 1890-Accepted, 10th May, 1890
A Weighing Device Applicable to Pocket-knives and the like.
A communication from FRIEDRICH ROBERT JAHN, of Dresden, Saxony, in the
Empire of Germany.
I, ALFRED JULIUS BOULT of 323 High Holborn in the County of Middlesex,
M.I.M.E., 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 relates to a device adapted to be applied to pocket knives and other
articles of daily use whereby the maximum weight of letters and packets to be
dispatched by post may be ascertained without the assistance of ordinary scales and
weights.
The device is so arranged that whenever it is desired to ascertain if a letter or
packet is within, or exceeds, the predetermined limits of weight-say half an ounce―
such letter or packet is attached to a needle or the like, which is either secured to a
special blade or inserted in an opening provided for the purpose in one of the existing
hlades of the knife, the body of which is moreover provided at a certain point
with a supporting knife edge. The knife is placed upon any suitable plane surface
for example on a table or the like in such a manner that the blade acting as a lever
swings freely while the knife proper lies on the table or the like, near the edge
thereof and with the blade forming as it were the beam of the scale, turned
downwards. The position of this blade in relation to the knife and the length of
the lever are previously adjusted so that when the letier or packet attains or
exceeds the predetermined maximum weight,-say half an ounce the knife is raised
from the surface supporting it, through the lever being drawn downwards. If on the
contrary the knife retains its original position on the said surface, it thereby signifies
that the maximum weight in question is not attained.
The device may obviously vary in the adjustment of its parts according to the limit
of weight it may be intended to indicate, and may be arranged for the control of the
weight of heavier articles. Thus it may be advantageously applied to the iron or
stone blocks or weights employed for keeping papers in place and in that case the
maximum weight indicated by it may be extended to the figure allowed for book-post
packets or parcels, and in fact attain ten pounds or more.
Various forms of this invention are illustrated in the accompanying drawing in
which
Figs. 1 and 2 respectively are a side elevation and a plan of a pen or
pocket knife A
fitted with a special blade a terminating in a fork b. When this knife is to be used
for weighing it is placed upon the table or like surface P with the blade c downwards.
Through the letter it is desired to weigh is then passed a needle d and the letter is
then conveyed into the fork so that it lies within the recess e and is thereby retained
in place. If its weight exceed the predetermined limit it will descend and carry down
with it the blade a whereby the part of the knife situated to the left of the blade cas
in figs. 1 and 2 is caused to rise. In the reverse case the knife remains in the same
position as before.
Fig. 3 is an upward view of a form of knife also provided with an additional blade a
but which is here adapted to move longitudinally within a guide f the limit of its
displacement being determined by a pin or stop movable in a groove or vice versa.
To the said blade a the knife edge c is rigidly attached while at its opposite end is
the point n whereon the letter or packet to be weighed is supported.
C
In figures 4 and 5 is represented the most simple form in which this invention
may be carried out. The knife is here only provided. with one knife edge c and one
cutting blade a in the latter of which one or more perforations are made. When it is

page_text: desired to ascertain the weight of a letter it is only necessary to insert an ordinary
pin into one of the said perforations so that it is prevented by its own head from
falling through; and on the other side of the blade the pin is passed through the
letter to be weighed. By providing more than one opening as aforesaid different
limits of weight may be set on the same device and the blade a in that case may
assume the shape of a graduated arm or beam whereon the different weights may
be engraved or otherwise depicted.
Figures 6 and 8 show a modification of this weighing device wherein the knife
edge c is replaced by two pins or studs c' which may in their normal condition lie
embedded in the knife casing m and be projected under pressure when required.
Within the knife these pins or studs are connected by a cross-piece or bridge c² acted
upon by springs c³ which keep back the pins. Over the said bridge c² is arranged a
wedge which may be displaced by means of a pin c when it is desired to press
forward the pins or studs c¹.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed as communicated to me by
my foreign correspondent, I declare that what I claim is ;-
1. In a pocket knife or the like a device whereby predetermined limits of weight
may be ascertained, consisting of a blade such as a to a certain point or portion of
which is attached the object to be weighed and of a supporting knife edge c upon
which the knife turns in the operation of weighing and whereby the body thereof is
raised when the predetermined limit of weight is exceeded substantially as described
and illustrated in the accompanying drawing.
2. In a device such as claimed in the preceding claiming clause the arrangement of
a special blade a with a forked end into which the letter to be weighed is inserted
after having a needle passed through it substantially as described, and illustrated in
the accompanying drawings.
3. In a device such as claimed in the first preceding claiming clause the arrange-
ment of two pins or studs such as c¹ connected by a bridge such as c² lying embedded
in the body of the knife or other article when out of use but capable when required
for weighing of being pressed outward into a projecting position substantially as
described and illustrated in the accompanying drawing.
4. The combination and arrangement of parts constituting the combined pocket
knife and weighing device substantially as described and illustrated in figures 12
or 3 of the accompanying drawings.
5. The combination and arrangement of parts constituting the combined pocket
knife and weighing device substantially as described and illustrated in figures 6, 7
and 8 of the accompanying drawings.
CA 1900
W. P. THOMPSON & BOULT,
Agents for the Applicant.