IMPROVEMENTS IN BALANCES
Year: 1884

page_text: I, HERBERT JOHN HADDAN, of the firm of Herbert and Company, Patent
Agents, of 67, Strand, in the City of Westminster, Civil Engineer, do hereby
declare the nature of said Invention for "IMPROVEMENTS IN BALANCES
" 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 balances or scales in which the differences of weight
are indicated by the position of a constant regulating weight.
In describing the Invention reference will be made to the accompanying
Drawings, of which Figs. 1 is a front view and partial section of the whole
apparatus, while Figs. 2 and 3 illustrate details.
The improved balance comprises a needle b fixed in the centre of the scale
beam a and performing a double function.
On the one hand it counterbalances, in its different inclinations, the small
differences which may exist between the contents of the scales c, o'; on the other
hand it indicates on a sector e the numerical value of these differences.
A graduated sector e or an are of a circle situated at the base of the apparatus
serves to indicate the distances travelled over by the needle or the weights
corresponding to these distances. The sector is divided according to the nature of
the fractions to be ascertained and according to the capacity of the scales; for
instance for scales of small capacity, capable to support about 4 oz. on each side, the
needle is adjusted to counter balance a penny weight, in its greatest inclination.
The point, where the needle stops, (with this weight in either scale) is marked at
the two extremities of the sector, and the distance from zero to each extremity of
the sector is divided into 24 parts, each representing one grain. The needle is thus
adapted to indicate in grains, from zero to one penny-weight, the differences
between the contents of the two scales.
Each division representing one grain is subdivided into minims by lines marked
on the sector.
Furthermore, the position of the needle between two subdivisions may be
accurately observed by the following arrangement :
The extremity of the needle has the shape of an isosceles triangle, as shown in
Fig. 3, the upper part (or base) of which covers the interval between two adjacent
[ Drine s

page_text: lines. This triangle is divided into zones of equal depth by the horizontal
lines a, b, c, d, e - - The larger the number of these lines and the closer the same
are to each other, the smaller will be the divisions.
This appliance operates as follows: The needle moves for instance, from the left
to the right, from the line m (that is the radial line passing through the point m) to
the linen (Fig. 3). When the line a touches with one end the line m, the point
of the needle has traversed one-tenth of the interval between m and n. When the
line in its turn touches the line m, the point of the needle has trayersed two-tenths
of the same interval. The line c indicates three-tenths and the line d four-tenths.
When the line e touches the line m, it touches at the same time the line n, and the
point of the needle is in the centre of the interval, (at five-tenths).
When the line d touches the line n, the point of the needle has covered six-tenths
of the interval; when the line e touches the line n it indicates seven tenths, the
line b eight-tenths, the line a nine tenths.
When finally the point of the needle reaches the line n, the whole distance
between (the radial lines marked by) m and n has been traversed by the needle.
For the purpose of controlling the movements of the balance, which is extremely
delicate, the same is provided with a brake constructed as follows. In the casing,
which supports the apparatus, are situated 2 parallel rods turning freely on their
axes and carrying near their ends the arms r¹ bent at right angles, and the
horizontal parts of which are equally parallel. The arms r r¹ are mounted obliquely
on the rods and converging towards each other clasp like a pair of pliers the
rigid vertical rods extending downward from the scales, thus producing on these
rods a slight friction which is sufficient to arrest the unsteady movements of the
scales. For the purpose of causing the arms to release the rods extending
downward from the scales, the parallel rods 7, are provided in the centre with
the levers xx¹, which may be lifted by means of the rod t connected with a button.
By this arrangement, the mechanism is kept immovable, to be released only when
necessary for use, and when the scales are perfectly steady. The rods holding the
scales are suspended to the arms of the balance lever by means of hooks p p¹, so
that the scale beam itself is kept steady.
Having now particularly described and ascertained the nature of the said
Invention, and in what manner the same is to be performed, I declare that what
I claim is:
1. Weighing apparatus having a needle connected with the scale beam and
adapted to equilibrate in its different positions small differences of weight existing
between the two scales or sides of the apparatus, and a graduated segment adapted
to show the inclinations of the regulating needle or the differences of weight
corresponding to such inclination, the whole being constructed and arranged
substantially as described.
2. In apparatus of the type described, the method of indicating minute variations
in the position of the needles, as illustrated by Fig. 3.
3. In apparatus of the type described, the brake or stop-mechanism, illustrated
by Figs. 1 and 2.
D: L
Tul 1001