SPRING BALANCES
Year: 1881

page_text: Tere by
of the Commissioners of Patents on the 29th October 1881.
JOHN LINACRE, of Brecon, South Wales, Civil Engineer.
SPRING BALANCES."
"IMPROVEMENTS IN
My Invention has reference principally to such spring balances as have circular
dial plates, on which the weight of the article is indicated by an index finger
traversing over a graduated circle on the dial plate.
My Invention is especially applicable to spring balances used for weighing heavy
bodies and articles, such, for example, as coal; and my said Invention consists of
the mechanical arrangements hereinafter described, whereby the sum or total
weight of the several weighings effected by the balance in a day or other period of
time is registered on the dial plate.
In the case of the balance a train of toothed wheels is situated, to which motion
is given by a toothed wheel on the axis carrying the ordinary or large index finger.
The several wheels of the train of toothed wheels may have any desired ratio
according to the purpose to which the balance is to be applied; for example,
in the weighing of coal the indicating dial may be divided into hundred weights,
quarters of hundred weights, and so on to any required minuteness of division,
while the toothed wheels described may be geared together by means of pinions,
the number of teeth in which is to the number of teeth of the wheels with
which they respectively gear as pounds to hundred-weights and hundred-weights
to tons.
The axes of the toothed wheels of the train described pass through the dial plate
and carry index fingers, which traverse small graduated circles on the dial plate.
The train of toothed wheels is provided with a ratchet wheels and pawl, so that they
can travel in the direction proper to register any weight carried by the balanco,
but are incapable of returning on the removal of the weight from the balance.
Rain 011

page_text: By this arrangement each weighing is added to the previous weighings, and the
amount of all the weighings is registered on the small graduated circles on the dial
by the fingers traversing them.
As the loading of the balance is usually attended with a considerable amount of
oscillation, which would cause a false registration, it is necessary for the accurate
performance of the machine that this oscillation should be prevented.
This is effected by causing the sliding bar to which the weight is suspended to
pass through a loop, which is pressed obliquely by a strong coiled spring and made to
grip the said bar and prevent its motion. After the balance has been loaded the
loop is turned out of its oblique position by the action of a lever operated by the
attendant when the sliding bar descends freely and the weight suspended to the
said bar is correctly registered.
Although my Invention is especially applicable to circular spring balances, yet
it may be applied to spring balances in which the weight is indicated on a vertical
graduated dial.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said John Linacre in the Great Seal Patent Office on the 19th April
1882.
JOHN LINACRE, of Brecon, South Wales, Civil Engineer.
SPRING BALANCES."
"IMPROVEMENTS IN
My Invention has reference principally to such spring balances as have circular
dial plates, on which the weight of the article is indicated by an index finger
traversing over a graduated circle on the dial plate.
My Invention is especially applicable to spring balances used for weighing
heavy bodies and articles, such, for example, as coal; and my said Invention
consists of the mechanical arrangements herein after described, whereby the sum
or total weight of the several weighings effected by the balance in a day or other
period of time is registered on the dial plate.
In the case of the balance a train of toothed wheels is situated, to which motion
is given by a toothed wheel on the axis carrying the ordinary or large index finger.
The several wheels of the train of toothed wheels may have any desired ratio
according to the purpose to which the balance is to be applied; for example, in
the weighing of coal the indicating dial may be divided into, hundredweights,
quarters of hundredweights, and so on to any required minuteness of division,
while the toothed wheels described may be geared together by means of pinions,
the number of teeth in which is to the number of teeth of the wheels with
which they respectively gear as pounds to hundredweights and hundredweights
to tons.
The axes of the toothed wheels of the train described pass through the dial
plate, and carry index fingers which traverse small graduated circles on the dial
plate. The train of toothed wheels is provided with a ratchet wheel and pawl,
so that they can travel in the direction proper to register any weight carried by
the balance, but are incapable of returning on the removal of the weight from the
balance.
By this arrangement each weighing is added to the previous weighings, and the
amount of all the weighings is registered on the small graduated circles on the dial
by the fingers traversing them.
As the loading of the balance is usually attended with a considerable amount of
oscillation which would cause a false registration, it is necessary for the accurate
performance of the machine that this oscillation should be prevented.
This is effected by causing the sliding bar to which the weight is suspended to
pass through a loop which is pressed obliquely by a strong coiled spring, and made
to grip the said bar and prevent its motion. After the balance has been loaded
the loop is turned out of its oblique position by the action of a lever operated by
the attendant, when the sliding bar descends freely and the weight suspended to
the said bar is correctly registered.
Although my Invention is especially applicable to circular spring balances, yet
it may be applied to spring balances in which the weight is indicated on a vertical
graduated dial.
I will now proceed to describe with reference to the accompanying Drawings the
manner in which my Invention is to be performed.
Figure 1 represents in front elevation and Figure 2 the same with the dial plate
removed a circular spring balance for weighing coal and other heavy bodies con-
structed according to my Invention; Figure 3 represents a transverse vertical
section of the same; and Figure 4 is a front elevation, partly in section, of the

page_text: same with the dial plate and train of toothed wheels and parts connected there-
with removed; Figure 5 is a back elevation of the balance, exhibiting the mechanism
for locking the sliding bar during the loading of the balance; Figure 6 is a
horizontal section; and Figure 7, a vertical section of parts of the locking
mechanism; Figure 8 represents in section and side elevation one of the toothed
wheels of the train and exhibits the construction of the ratchet gear used with the
said train for preventing the upward or return motion of the sliding bar being
transmitted to the train of wheels as hereinafter particularly explained.
The same letters of reference indicate the same parts in the several Figures of
the Drawings.
с
a is the circular case of the balance carrying the loop b by which the balance is
suspended; c is the sliding bar to which the material to be weighed is suspended.
The sliding bar c is connected to the cross bar d to which the lower ends of the
strong coiled springs e, e, are secured, the upper ends of the said springs being fixed
to the cross bar fin the usual way; c² is the rack jointed at c³ to the sliding bar c,
the teeth of the rack being pressed into contact with the pinion g by the spring h
(see Figure 4). On the axis of the pinion g is an index finger i, which, on the
motion of the rack c, traverses the large indicating dial plate which is divided
into hundredweights and parts of hundredweights. By the descent of the sliding
bar c and rack c, the springs e, e, are elongated and the weight upon the balance
is registered by the index finger i upon the dial plate k by the motion of the
rack gearing with and giving motion to the pinion g on the axis of the said
index finger as is well understood. After each weighing the index finger i returns
to the zero point on the dial plato k.
The sum or total weight of the several weighings effected by the balance in a
day or other period of time is registered on the dial plate in the following
manner: On the dial plate k are other small dials l, m, index fingers n and p
traversing the said dials l, m. The dial is used for indicating tens of hundred-
weights, and the dial m is used for indicating tons. The motion of the axis of the
pinion g carrying the index finger i is transmitted to the axes of the index
fingers n, p, in the required ratio by the train of toothed wheels, best seen in
Figure 2, that is to say, on the axis of the pinion g is a toothed wheel g² which
gears with the loose tooth wheel g³ on the axis of the pinion q.
This pinion q
gears with the toothed wheel q on the axis carrying the index finger n.
motion of the axis r is transmitted through the small toothed wheel q³, larger
toothed wheel q, pinion 9, and toothed wheel 96, to the axis s carrying the index
finger p. The train of toothed wheels represented can travel only in the direction
proper to register any weight carried by the balance; the said train of wheels being
prevented from returning or making a back motion on the removal of the weight
from the balance, and when the rack bar c makes its ascending motion. This is
effected by the arrangement of ratchet gear shown in Figure 2, and section and
clevation in Figure 8.
Tho
The toothed wheel g³ with which the wheel g² on the axis of the pinion g gears
is loose, as before described, on the axis of the pinion q, and on opposite sides of
the said loose toothed wheel g² are ratchet wheels t, u, fixed on the axis of the
pinion g. The ratchet wheel t is on one side of the loose wheel g³, as shown in
Figure 2, and in the section of Figure 8, and the other ratchet wheel u is on the
other side of the loose wheel g³, as shown in the elevation of Figure 8. The teeth
of the ratchet wheels t, u, are turned in opposite directions. On the face of the
loose toothed wheel g³ are driving pawls v, v, which are pressed into the teeth of
the ratchet wheel t by the springs represented; and on the fixed carrying plate
of the train of toothed wheels retaining pawls y, y, are situated, which pawls y, y, are
pressed into contact with the teeth of the ratchet wheel u by the springs repre-
sented. The result of this arrangement is that on the descent of the rack c² the
loose toothed wheel y³ is carried forward, and by the action of the driving pawls v, v,
on the said wheel g³, the ratchet wheel t also is carried forward through tho
required angle together with the pinion q on the same axis. As the ratchet wheel t

page_text: is thus moved forward the other ratchet wheel u on the same axis is moved with
it, but as the teeth of the ratchet wheel u are turned in an opposite direction to
those of the ratchet wheel t, the pawls y, y, of the said ratchet wheel u slip over
the teeth of that ratchet wheel. When the weight is removed from the balance
and the rack c² makes its upward motion the loose toothed wheel also makes a
back or return motion, restoring the large index finger to the zero point, but this
back motion is prevented from being transmitted to the axis of the pinion q by the
pawls y, y, which now engage with the teeth of the ratchet wheel u, the driving
pawls v, v, slipping over the teeth of the other ratchet wheel t.
By the construction and arrangement of parts described and represented, each
weighing effected by the balance is added to the previous weighings, and the
amount of all the weighings is registered on the small dials l, m. The complete
rotation of the index finger i indicates that ten hundredweights have been weighed,
the complete rotation of the index finger n indicates that ten tons have been
weighed, and the complete rotation of the index finger p indicates that one hundred
tons have been weighed.
In Figure 1 the large indicating finger i is represented at zero, and the finger n
also at zero, and the finger p traversing the dial m indicates that ten tons have
been weighed.
After the sum or total weight of the several weighings effected by the balance in
a day or other period of time has been registered, as described, it is necessary on
again using the balance to bring the index fingers n, p, to their respective zero
points; this is done by prolonging the axis of the pinion q³ through the principal
indicating dial plate k, as seen in Figure 1, where the prolonged part of the axis is
marked w, and making the said prolonged part square for the reception of a key.
By turning the axis of the pinion q by a key fitted on its square end w, the train
of toothed wheels may be turned so as to carry forward the index fingers n, p,
until they are brought to their respective zero points; the balance is then ready to
commence a series of fresh weighings.
Although I have represented the arrangements of the dial plate and dials k, l, m,
and train of toothed wheels which are suitable for the weighing of coal and other
heavy commodities, yet I do not limit myself to those arrangements, as the several
toothed wheels of the train may have any desired ratio according to the purpose
to which the balance is to be applied.
I will now describe the mechanism by which the oscillation of the sliding bar of
the balance is prevented during the loading of the balance. The sliding bar c
passes through the swivelling loop z, the axis a³ of which turns in bearings a², a²,
at the lower part of the balance case a. On the axis a³ carrying the swivelling
loop is an arm at which is pressed down by the strong coiled spring a³ around
the rod a. The spring as takes an abutment at bottom against the arm a', and at
top against the fixed bracket a² on the back of the balance case (see Figure 5).
By the pressure of the spring a upon the arm at the loop z is made to take the
oblique position represented in Figures 2, 3, 4, and 5, and thereby to grip the
sliding bar c and prevent its motion. After the balance has been loaded the
swivelling loop z is turned out of its oblique or locking position, as illustrated in
Figure 7, when the sliding bar c is released and descends freely, and the weight
suspended on the said bar is correctly registered. The releasing or unlocking of
the swivelling loop z is effected by the attendant pulling down the lever as by
means of a chain or cord attached to the end of its long arm. The short arm of
the lever as is jointed to the prolonged end of the rod a around which the coiled
spring is situated. By the depression of the lever a³ the rod a and arm a* are
raised and the spring a compressed, the raising of the arm a turning the loop =
into the unlocking or horizontal position represented in Figure 7.
The mechanism described and represented for preventing the oscillation of the
sliding bar of the balance during loading may be applied to spring balances
generally.
Having now described the nature of my Invention, and the manner in which

page_text: the same is to be performed, I wish it to be understood that I claim as my
Invention of "Improvements in Spring Balances,”-
First. The combination with or addition to spring balances of the mechanical
arrangements of parts herein before described and illustrated in the accompanying
Drawings, whereby the sum or total weight of the several weighings effected by
the balance in a day or other period of time is registered on the dial plate of the
balance, the several parts being constructed, arranged, and operating substantially
as described and illustrated.
Secondly. The construction and combination of the parts of mechanism herein
before described and illustrated in the accompanying Drawings, for preventing the
oscillation of the sliding bar of the balance during the loading of the balance.
In witness whereof, I, the said John Linacre, have hereunto set my hand and
seal, this 14th day of April, in the year of our Lord One thousand eight
hundred and eighty two.
Witness,
W. MORGAN,
Brecon,
JOHN LINACRE. (L.S.)