AN IMPROVED MACHINE FOR WEIGHING, WITH THE MEANS OP KEEPING & REGISTER OF THE OPERATIONS OF THE INSTRUMENT
Year: 1834

page_text: DEBAC
ION.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, PIERRE
BARTHELEMY GUINIBERT DEBAC, of Acre Lane, Brixton, in the County of
Surry, of the Polytechnic School, Paris, send greeting.
WHEREAS His present most Excellent Majesty King William the Fourth,
by His Letters Patent under the Great Seal of Great Britain, bearing date
at Westminster, the Twenty-sixth day of July, in the fifth year of His
reign, did, for Himself, His heirs and successors, give and grant me, the
said Pierre Barthelemy Guinibert Debac, His especial licence that I, the
said Pierre Barthelemy Guinibert Debac, my exors, admors, and assigns, or
such others as I, the said Pierre Barthelemy Guinibert Debac, my exors,
admors, or assigns, should at any time agree with, and no others, from time to
time and at all times during the term of years therein expressed, should and
lawfully might make, use, exercise, and vend, within England, Wales, and
the Town of Berwick-upon-Tweed, my Invention of "AN IMPROVED MACHINE
FOR WEIGHING, WITH THE MEANS OP KEEPING & REGISTER OF THE OPERATIONS OF THE
INSTRUMENT;" in which said Letters Patent is contained a proviso obliging
me, the said Pierre Barthelemy Guinibert Debac, by an instrument in writing
under my hand and seal, particularly to describe and ascertain the nature of
my said Invention, and in what manner the same is to be performed, and to
cause the same to be enrolled in His Majesty's High Court of Chancery
within six calendar months next and immediately after the date of the said
recited Letters Patent, as in and by the same, reference being thereunto had,
will more fully and at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said

page_text: Pierre Barthelemy Guinibert Debac, do hereby declare the nature of my
said Invention to consist in a vertical loaded balance beam acted upon
near its fulcrum by a horizontal balance beam, from which said horizontal
balance beam the scale platform or other support for the body which is to be
weighed is suspended, the vertical beam being moreover so arranged with
an index at one end and a registering apparatus at the other, that the
oscillations of its two ends gives the weight sought and register the opera-
tions of the instrument at the same time, the result of which combination
of apparatus is, that all bodies may be weighed thereby within certain limits
by means of an invariable balance weight, which is so circumstanced as to
serve as a common measure to them all, and at the same time to give the
amount of weight and register 'the operations of the instrument by the sole
agency or presence on the machine of the body to be weighed. The theory
on which this instrument is founded, is as follows:-Let us consider a lever
with unequal arms (E Sheet, Figure 1) 2, the fulcrum of which, is in O, the
two arms OA and O I. Suppose a weight placed in I, and different forces
applied to A; then the condition for equilibrium, whatever may be the angle
contained by the two arms, assuming O I, R, OA=r P, the constant weight
PR sin a
applied to I will be Q=
Sin 2 calling x and x' the respective angles
contained by R and r and the vertical line. If, now, we suppose that the
angle contained by the two arms should be a right angle, then sin x¹ becomes
cos x, and the formula is changed into Q=-
P. R
7"
Xtang x, which is the case
already known of levers with unequal arms. But if we suppose that the
direction of the force applied in A should in all the different positions assumed
by the lever be constantly perpendicular to the arm, then the formula becomes
PR
= xsin x, a formula which we still obtain if we suppose that when
r
the arm I assumes different positions, the point of application of the force
should always remain on a certain point A' of the horizontal O A', for in the
PR sin x
formula Q=
is always a right angle, sin x'=1. Let us
sin"
Qr
now assume in the formula sin x=.
PR
r
but, as
R=1, and.
y, then it becomes
sin ay. r, a formula which signifies that in such a system of levers with
unequal arms, the forces applied as described are as the ares which correspond
to the sines of the angles made by the lever, charged with the weight and the
vertical line which passes by the fulcrum. But if we suppose R great with
respect to r, and if we limit ourselves to a few arcs situated in the first part of

page_text: the circumference, then we shall have arc x=siu x, and also sin 2x=are 2x,
and even arc 6x=sin. 6; this will be evident if we consider the following
formula:-
arc sin x, 1 sin r
+
1. 2. 3
+
128² sin 5.x
++
1. 2. 3. 4. 5
{are=sin
1283.. (2-1) sin +11
1. 2. 3... 2 u+1
For more information see the treaties on mechanics, differential calculus, and
trigonometry. Then, finally, we may assume, limiting ourselves, as I have pre-
viously observed, to a few arcs situated in the first part of the circumference, that
"the forces applied are as the arcs described by the centre of gravity of the
constant weight, that is to say, for a double force we have a double arc, &c."
Having then described an arc of a circle with a radius, suppose 25, r, and r
an inch, then (Fig. 2) from the point A, and with a pair of compassess of
which the points are an inch distant from each other, we mark 5 arcs, by the
extremities of which the centre of gravity of the weight is to pass, when the
forces applies to rare successively P', 'P, "P, 'P, 'P, such is what may be
considered new in the theory of the pondometer, which I shall conclude by
the following remark, the result of many skilful experiments made by Mr.
Toplis, of the Museum of Arts, Leicester Square, London:-"That when axes
are terminated by cones and work into cylinders, the friction is equal to
of the weight which presses such axes."
And in further compliance with the said proviso, I, the said Pierre Barthe-
Jemy Guinibert Debac, do hereby describe the manner in which my said
Invention is to be performed, by the following statement thereof, reference
being had to the Drawings annexed, and to the figures and letters marked
thereon, it being observed that similar letters are used to denote similar parts
in all the Figures.

page_text: as light as is consistent with stiffness, and fixed solidly to the disc, are of
equal lengths, and their axes in the same line; they each carry at their outer
extremities an arc (c, c,) set on sides of the arms contrary to each other, but
both in the plane of rotation of the beam. The position at rest of this beam
being vertical, we will for distinction call it the "vertical beam." To the
extremity of the lower arm is attached a mass of metal spherical or of other
suitable form, the centre of gravity of which coincides with the extremity of
the radial axis of the arm. This mass serves as the constant weight of
admeasurement (D). The arc of the upper arm is furnished with a mounted
screw at one or both ends, the screws being drilled lengthwise to admit the
ends of a fine chain, the tension of which they may regulate, or other con-
trivance for the same purpose of adjustment may be adopted; equivalent
weights to these screws must be put on the lower arc as a counterpoise. The
second piece of this mechanism is a straight lever mounted on an axis similar
to that of the vertical beam above described, and of the same length (Fig. 2).
The position of this lever is horizontal, and the extremity of its acting arm is
to operate on a horizontal radius of the disc of the vertical beam, so as to
deflect the beam and constant weight from their position of rest. For this
purpose I make use of a fine chain pinned to the periphery of the disc near
the springing of the upper arm, and its other end attached so as to touch the
lower part of the segment of a circle described on the end of the lever from its
centre of motion, so that the leverage through the extent of motion shall be
uniform (e, Fig. 1). The horizontal lever has a counter arm beyond the
fulcrum to carry a counterpoise, in order to neutralise the matter of the lever
and its appendages (+ Fig. 2). The third piece which we have to describe is
a rod or link, through which the weight to be examined is brought to act
upon the horizontal lever. At its upper end this rod has a loop or eye (m),
through which the acting arm of the lever passes, and, being furnished at the
upper margin of the loop with a hardened steel point or knife-edge pointing
downwards (n), it is thereby made to rest upon the lever at a definite point by
means of an indentation. Lower down in this rod there is another such loop
or eye (o, Fig. 3), if it be necessary to clear the end of the lower arc on the
vertical beam, and the lower extremity may terminate in a fork with a cross
pin or bolt (p) whereby to attach the link or rod of a scale or platform
destined to receive the body to be weighed. The weight of these several
appendages must be neutralised by the counterpoise (t) on the outer arm of
the horizontal lever. This rod may be called the suspension rod (E). The
axes of the vertical beam and of the horizontal lever are supported in a
common frame composed of a bottom plate and two upright standards screwed

page_text: or bolted together. The bottom plate (F, Fig. 4, Sheet B) is of an oblong
form, with an elongated aperture to allow the passage of the lower arm of the
vertical beam and of the suspension rod, and bas four bolt holes at its corners
to fix it upon another framing. The two standards or side plates (G) screwed
or bolted to the bottom by their feet or lugs, stand up parallel to each other
from the opposite margins of the long opening; they have a ledge turning
outwards at the upper sides. The two standards are connected above by two
inserted bridge pieces (a, Fig. 5), screwed by their lugs to the ledges of the
standards. Holes are drilled and tapped through the upper parts of the standards
and bridge pieces to receive steel screw pins, which serve for bearers to the axes
of the vertical beam and of the lever, in the way above described; or if these axes
are supported on antifriction wheels, the holes are left open to allow passage
to the cylindrical arbours, the cross plate at the bottom of the bridge piece,
which is connected with the bearing of the vertical lever, is scooped out on
one side to free the lower arm, and that of the horizontal lever will require
the same when the suspension rod comes very near to the fulcrum of the
lever. A guide plate may be fixed from standard to standard to prevent the
loop of the suspension rod from swerving when it hangs on the lever by a
single point. To the bottom plate of the common frame is screwed a depend-
ing flat bar, Fig. 6, in such a situation that its outer edge lines with the
longitudinal axis of the vertical beam, and at its lower end it carries an arched
piece of the same curve as the arcs of the vertical beams. The length of
this bar is such that the arc of the lower arm of the vertical beam just shews
itself above the arc of the bar, whereby the degrees marked thereon may be
seen. This arched piece may be called the regulating arc x; its use will be
explained in speaking of the construction of the machine (u, Fig. 6). Over
the place of the depending bar rises another, screwed to the common frame,
which rises somewhat above the arc of the upper arm of the vertical beam
(H, Fig. 7). On the flat or cross at the top of this bar are fixed the dial (p)
and index (1), by means of which the weights are indicated. Behind the
dial and coinciding with its centre, fixed in a cock piece screwed to the bar,
is a small cylinder (s), lying across the are of the vertical beam, its slender
axis protruding through the central hole of the dial to carry the index.
Round this light cylinder is wound a silk cord or a fine chain, the ends of
which are made fast to the two screws at the extremities of the arc, or they
may be attached in any other way which will leave the means of adjusting
the tension of the cord or chain in such a manner as that the angular motion
of the arc shall cause a correspondent rotation of the cylinder without
failure. On the face, in front of the arc, is a projecting pin, coming through'

page_text: an arched notch in the dial plate, whereby the number of revolutions of the
cylinder is indicated on a graduated arc. The graduations on the margin of
the notch mark the integral weights, those round the dial the subordinate
parts. To protect the machinery the whole of this portion may be inclosed
in a case like that of a house clock, leaving visible through a window only
the dial. When the pondometer is appropriated to the weighing of heavy
goods, the platform on which they are to be received should be on a level
with the floor, and beneath it must be the common mechanism of a weigh
bridge, so arranged that the load is brought to act upon the suspension rod
of the pondometer. Similar contrivances will also fit it for use on the counter
of a shop. When the registering machinery is appended to the pondometer,
the dial and its connections are dispensed with, and then the weighing appa-
ratus may be placed altogether out of observation, in such situation as will
conform best with its immediate connection with the weigh bridge.
I will now proceed to describe the registering apparatus. The object of
this part of the mechanism is to record the result of each operation during a
certain time. To receive this record, paper is the most convenient material,
and the machine has therefore to effect two operations: to mark upon the
paper the record of each weighing, and to cause the paper to travel, so that
it may receive in due succession the whole series of records. The part which
produces the record consists of a cylindrical, spiral, or helix, making one
revolution round an axis, and which in its revolution depresses in succession
a series of levers armed with prickers or points, which make their marks
upon the paper placed to receive them. The part which changes the situation
of the paper consists of three rollers, and contrivances to give them motion
after each operation. The spiral or helix (I, Sheet C) is made of small tube
for lightness, curved helically round an axis or shaft, and supported by arms
of equal length, so that the helix completes one revolution in the length of
the cylinder. The spindle of the helix is mounted in a frame, through one
side of which it passes, and is placed in such a way as to carry just over the
arc of the upper arm of the vertical beam a pulley with two grooves on its
periphery (J), beyond which is a dial to shew the indications of the weights
on the outside. Round the two grooves of the pulley are wound two chains
or cords, one end of each being attached to the pulley, the other ends respec-
tively to the two extremities of the arc, by which arrangement the alternating
angular motion of the arc conveys in either direction rotatory motion to the
spindle of the belix. The system of marking levers (N) consists of a number
of similar thin steel bars, moveable on a common rod as a fulcrum, and
mounted on a particular frame, two tenons from the ends of which drop into

page_text: This
grooves into the outer frame, the lever frame, by means of an end screw (v),
being susceptible of a little end motion to adjust the position of the levers to
the indications of the dial. The system of levers is placed below the spiral
in such a situation as to allow the helix to press upon them in succession, as
its following line approaches the lowest point of the cylindrical space in which
its revolution is performed. The arms of the marking levers are so nearly
balanced as to leave to the back arms only so much preponderance as suffices
to raise the marking arm to its proper place of rest on being left by the helix.
The marking arms of the levers project so far beyond the plane of the axes of
the spindle and of the subjacent roller as to allow the helix to act upon them
in the same manner in either direction of rotation. Immediately beneath the
levers the line of whose points is in the plane of the axes, is placed a roller (K),
the surface of which is covered with caoutchouc or other elastic matter.
roller can be made to approach or recede from the line of points, its pivots
resting upon the arms of two levers, which are elevated or depressed by screws
acting upon the opposite arms (k, k). Below this roller are two others
(L, M,) the gudgeons of which project some distance beyond the framing on
the end opposite to that where the dial is placed. These two rollers hold the
stretch of paper which is fixed on them at its extremities by two longitudinal
bars dropping into grooves to receive the points, giving and taking the same as
they are put temporarily in motion; the lower roller is charged with the
sheet of paper in the first instance, and gives it up as the other roller
takes it. The paper having been impressed by the action of one revolution
of the helix on the series of levers, it becomes necessary to present a new
surface to receive the succeeding impression of the prickers in the following
operation. This is thus effected: -On the gudgeons of the two paper
rollers which project beyond the frame, are two pullies or barrels (O, P),
around each of which a cord is wound in opposite directions on each barrel,
the cords carrying weights at their loose ends. The weight of the upper
pulley or barrel is double that of of the lower one. Its office is to cause the
upper roller, when liberty of motion is given, to take up the paper which has
received impression, whilst the lower. roller gives out the new paper, the
weight appended to the latter keeping the paper in a proper state of tension.
The barrel of the lower roller is fixed upon its gudgeon, the quantity of
pendent cord being sufficient at the commencement for the whole motion which
it has to undergo, the weight being raised as the paper is given of. The barrel
of the upper roller is loose upon the gudgeon, and only fixed there by a click
and ratchet wheel attached to the gudgeon, which, when liberated, allows the
weight to be drawn up again by the counteracting force. On the side of the

page_text: upper barrel next to the frame is attached a toothed wheel of the same
diameter, which works into a pinion placed above it fixed on the same axis
with another wheel which drives another pinion attached to a circular disc, on
the outer side of which is a snail, the spiral of which commences near the
centre, and having described one revolution, forms a drop at its termination
that serves as a stop when opposed to the end of a lever (Sheet D, Fig. 1).
On the face of the drop is a small roller to facilitate the rise of the stopping
bar when it is to be liberated, the snail being constantly urged to revolve by
the weight acting on the upper barrel. The axes of the above train of
wheels lye in one vertical line, which is the same as that of the rollers above
the snail, and in the same. plane is a lever of the first order (a, Fig. 1),
extending the length of the frame, and having its fulcrum on a pin fixed
thereon. The end of this lever, which comes in opposition with the drop of
the snail, is slightly rounded. When this is made to rise, the weight of the
upper roller causes the snail to revolve, and having made one revolution, it is
again stopped by the end of the lever, which suspends also the motion of the
rollers. The tripping of the stop. lever, and consequently the progression of
the paper, is caused by the return motion of the helix depressing the end of a
lever (b, Fig. 2), placed on the inside of the frame a little above the position
of the outer lever; and parallel with it a stud, betwixt the fulcrum at its outer
extremity and the point of action of the helix, projects through the side of
the frame, and rests upon the tail of the outer lever. A catch, yielding in one
direction on the moveable end of the inner lever, gives way to the pressure of
the helix in its first direction, but on the return resists and causes the depres-
sion of the lever which by the projecting stud trips the stop lever and allows
the revolution of the snail (N, Fig. 1). The paper is thus moved onwards
when it has received the impression, and when none of the prickers are in
contact with it. It may be remarked here, that the vertical balance beam, as
I now present it, is virtually a circular body revolving on its centre, and that
if I have retrenched two large segments of the same, it has been with the
view of rendering the construction more easy, the weight less, and the bulk
more compact; the use, besides, of an entire circle would entail the necessity of
placing the central disc in a different plane, which would render the action
less true.
Further I would observe, that the use of the horizontal level is
not absolutely necessary to complete the pondometer, for a scale dish attached
to the chain or cord of the central disc to receive the body to be weighed, or
any other convenient mode of bringing the uncertain weight to act directly
upon the circumference of the disc would effect the purpose of weighing, but
subject to too much motion in both the constant and the inconsistent weight,

page_text: to unsteadiness of motion, and so on, all of which inconveniences are avoided
or lessened by establishing the motion through the intervention of a lever of
unequal arms.
When the pondometer is applied to a weigh bridge in connection
with its registering machinery, it becomes necessary, to prevent confu-
sion in the register, to prevent the weight of the draught animal from
acting thereon. To attain this object I have contrived an addition to the
weigh bridge of a narrow unyielding bridge, resting on opposite sides of the pit
over which the animal passes, the wheels bearing the load only coming to
bear
upon the platform, and so acting upon the register.
In the annexed Drawings Sheet A exhibits the principal parts of the
pondometer apart; Sheet B, other parts detached; Sheet C, a side elevation
of the registering apparatus; Sheet D, of the roller case of the register, to
shew the mode of bringing successive portions of paper under the prickers;
Sheet E, side and end elevation of the pondometer.
Having now described the parts in detail and mode of action of my
improved weighing machine, it will be necessary to advert to some general
principles of government in the construction thereof, in order that it may
accord in practice with the theoretical principles. For the construction of
this machine it will be necessary to determine the length of the arms of the
vertical beam by means of the radius of the disc, which radius is itself deter-
mined by the length of the centre arc which we cause to be described by the
centre of gravity of the constant regulating weight, bearing in mind that this
are must not be too great, in consideration of the oscillations which would be
caused by the force of descent when great weights came to be weighed. The
equality of the arcs described depending upon the length of the arms of the
vertical beam, it will be necessary to assign to these latter such a length as
shall comply with such equality, considering always that as these successive
arcs must be spread out over a certain number of repetitions of an extended
circle, the difference between the first and the last division should not shew
more than an almost inappreciable quantity. Let us suppose, for example,
that, the whole are being five inches, the difference betwixt the first inch and the
last were ou of an inch, this are being spread out over five circumferences of
the dial extending to one hundred and fifty inches, we shall have betwixt the
first and the last circumference a difference thirty times greater, or of an
inch. The weight of the constant regulating weight will be decided by two con-
siderations: first, the friction which it will cause upon the bearings; secondly,
the oscillations. To ascertain the greatest amount of friction which it will

page_text: cause upon the pivots, multiply the weight by the number of arcs into which
the regulating arc has been à priori divided, and then divide by four hundred
and fifty; see theory. As to the oscillations, they will depend upon the
length of the vertical beam, which the longer it is the larger regulating weight
it will require to check the vibration. Experience in this case will be the
best guide. The arcs fixed on the extremities of the arms of the vertical beam
should be a little longer than the proposed entire are of vibration or range of
motion, in order to be able to attach to the upper arc the means necessary for
communicating the whole of its motion to the index. After having deter-
mined by calculation (see theory) the radius of the disc and the arms of the
vertical beam, it will be easy to establish the regulating arc, which, being one
composed of sines, is obtained geometrically; but it is necessary to remark
that when sine x is small in proportion to the radius, and also that in the first
part of the circumference, when sine x-arc x, it will be sufficient, after
having determined the radius of the disc, and described an arc with a radius
equal to that of the vertical beam to which we are confined, to set out upon
this arc with an opening of the compasses equal to the sine as many times
that space as calculation shall have shown us that these ares may be considered
equal, and the sum of these ares will form the regulating arc. We have
restricted ourselves to the five first arcs. This regulating arc is of great use,
for it serves to point out errors in the construction of the machine. In fact,
if we take a weight of one pound, and fix it as the regulating weight, and to
the chain of the disc we suspend a scale disb, on placing therein succes-
sively 1, 2, 3, 4, 5 pounds, the centre of gravity of the weight will stop in suc-
cession at the first, second, third, fourth, and fifth sines. With regard to the
index, the only important thing is the small cylinder which we have adopted;
its pivots should be small to cause the least possible friction, and its circum-
ference equal to one part of the arc given by the number of revolutions we
wish to obtain; that is to say, the number of revolutions being five, the arc
five inches, the circumference of the small cylinder will be equal to one inch.
All the other parts of this machine being, as I have described them, well
known in mechanism, it is not necessary to speak further of them; and also on
the construction of the several pieces of the registering machinery it will be
only needful to remark that the helix should be so formed as that, in the
course of one revolution, every point of the spiral should have come in contact
with the line of levers placed beneath it. It should besides be made as light
as possible. The one now made weighs seven ounces. The necessity for this
lightness of construction arises from the circumstance that the resistance

page_text: offered by the movement of this piece acts constantly at the extremity of a
long lever whilst the moving force is applied to the end of a short one.
From
this consideration also the register cannot mark from zero, but from a certain
point above determined by a quantity obtained from the weight of the helix
and of the combination of levers; for example, the helix weighing seven
ounces, it will require 36 oz. to set it in motion. But as we have for the
ratio of the long to the short lever 25:1, we must multiply this fraction
by 25, which will give us or oz. Add to this the friction on the
levers, and it will give the amount of force necessary to put the helix in
motion. When the force is applied to the circumference of the disc through
a lever, it will be necessary to multiply this again by the ratio of the arms of
the horizonal lever. This shews us that in the application of the pondometer
to the registering machine we must avoid, first, giving too great length to the
arm of the vertical beam, and, secondly, making the ratio of the arms of the
horizontal lever too great, in order to expend as small a quantity of force as
possible in turning the helix. This is all which appears necessary to be said
on the construction of this machine.
Now whereas it is evident that the size and strength of the pondometer and
of its different parts may be varied as occasion may require with reference to
its being used for heavy or light goods; and whereas it is equally evident that
various modifications of the instrument might be adopted suitable to the
particular circumstances under which it is to be used, all equally involving the
principle of the said Invention which I hereby claim to be mine, and declare
to be,―
First, the vertical beam moveable on a centre in one plane, and loaded with
one constant weight, and which is acted upon by the weight of the body to be
weighed through the medium of a lever applied near to the fulcrum of the
said vertical beam, as herein-before described, the extent of the angular
motion of which beam marks the weight of the said body, and causes the
registering apparatus to act by the sole agency or pressure on the machine of
the body to be weighed. And,
Secondly, the said registering apparatus.
And such my Invention being, to the best of my knowledge and belief,
entirely new, and never before used within that part of His said Majesty's
United Kingdom of Great Britain and Ireland called England, His said
Dominion of Wales, or Town of Berwick-upon-Tweed, I do hereby declare
this to be my Specification of the same, and that I do verily believe this my
said Specification doth comply in all respects fully and without reserve or
disguise with the proviso in the said herein-before in part recited Letters

page_text: Patent contained: wherefore I do hereby claim to maintain exclusive right
and privilege to my said Invention.
In witness whereof, I, the said Pierre Barthelemy Guinibert Debac, have
hereunto set my hand and seal, this Twenty-first day of January, in
the year of our Lord One thousand eight hundred and thirty-five.
AND BE IT REMEMBERED, that on the Twenty-first day of January,
in the year of our Lord 1885, the aforesaid Pierre Barthelemy Guinibert
Debac came before our said Lord the King in His Chancery, and acknow-
ledged the Specification aforesaid, and all and everything therein contained
and specified, in form above written. And also the Specification aforesaid
was stamped according to the tenor of the Statute made for that purpose.
Inrolled the Twenty-sixth day of January, in the year of our Lord
One thousand eight hundred and thirty-five.