IMPROVEMENTS IN SHORT LEVERS WEIGHING SCALES
Year: 1869

page_text: LETTERS PATENT to Michael Kennedy, of New York City, in the
City, County, and State of New York, in the United States of
North America, for the Invention of "IMPROVEMENTS IN SHORT
LEVERS WEIGHING SCALES."
Scaled the 29th October 1869, and dated the 28th June 1869.
PROVISIONAL SPECIFICATION left by the said Michael Kennedy
at the Office of the Commissioners of Patents, with his Petition,
⚫ on the 28th June 1869.
I, MICHAEL KENNEDY, of New York City, in the City, County, and
State of New York, in the United States of North America, do hereby
declare the nature of the said Invention for "IMPROVEMENTS IN SHORT LEVERS
WEIGHING SCALES," to be as follows:-
All my improvements are directed to the same object, viz., that of
securing to short lever weighing scales the most perfect accuracy, and
which cannot be otherwise obtained.
They consist, 1st, in giving a particular inclination to the fulcrum
pivots of certain of the levers and to their bearings, necessitating a
special form and construction of the standards or lever plates. Each
A

page_text: bearing should have the same inclination with that given to the fulcrum
pivot of the lever which bears upon it. This inclination corresponds
with the direction of the thrust, and is determined as follows:-Lines
being drawn joining the pivots of the lever arms to each other and to
the fulcrum pivot, a right-angled triangle is obtained, whose right angle
is at the fulcrum pivot; complete the parellelogram, and from the
fulcrum pivot draw the diagonal to the opposite angle. The direction
of this diagonal gives the required inclination of the fulcrum pivot and
of its bearing.
2nd. In the form, construction, and method of application of the
adjusters to the levers. One of the pivots of the lever is carried in the
adjuster, the sliding or movement whereof when attached to the lever
lengthens or shortens the lever arm to which it is attached, whereby in
sealing the scales the levers are adjusted to one another. To prevent
this pivot from getting out of the right line during the movement of
the adjuster, I provide the latter with jaws or guides, or other equi-
valent, which hold it in line on the lever during the process of
adjustment.
3rd. In the form and construction of the connecting rods, so that the
levers may be connected with one another through said rods without.
removing the pivots. To obtain this result the main rod is furnished
with an eye at each end, open links are constructed, also furnished at
each end with a corresponding eye, the bearing block is placed in the
link, which is then passed over and around the pivot without disturbing
it, and the link is then connected to the main rod by a bolt, or its
equivalent, passing through the eyes.
4th. In transmitting the action of the weight or load by tension and
compression at the same time when required, and in the form and con-
struction of the rod destined for that purpose. When the lever which
serves to transmit the action of the load to the beam or to another lever
is placed between the two second levers (which are then arranged
in similar directions), one of them transmits the action of the load
by tension upon the rod connecting it, the other by thrusting against
the rod or by compression. To prevent the thrust from twisting or
deflecting the rod, whereby the accuracy of the scale would be destroyed,
I employ a tube, or its equivalent, in place of a simple rod to connect
the thrusting second lever.

page_text: 5th. In providing shoulders to each pivot of the levers so as to prevent
contact between the bearings and the iron of the lever. For this
purpose shoulders are formed on the pivots at places nearest the levers
where the bearings would touch the levers were the shoulders not formed
there to prevent such contact.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Michael Kennedy in the Great Seal Patent Office
on the 28th December 1869.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, MICHAEL
KENNEDY, of New York City, in the City, County, and State of New
York, in the United States of North America, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-eighth day of June, in the year
of our Lord One thousand eight hundred and sixty-nine, in the thirty-
third year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Michael Kennedy, Her special
license that I, the said Michael Kennedy, my executors, adminis-
trators, and assigns, or such others as I, the said Michael Kennedy,
my executors, administrators, or assigns, should at any time agree
with, and no others, from time to time and at all times thereafter
during the term therein expressed, should and lawfully might make,
usc, exercise, and vend, within the United Kingdom of Great Britain
and Ireland, the Channel Islands, and Isle of Man, an Invention for
"IMPROVEMENTS IN SHORT LEVERS WEIGHING SCALES," upon the condition
(amongst others) that I, the said Michael Kennedy, my executors or
administrators, by an instrument in writing under my hand and seal,
should particularly describe and ascertain the nature of the said In-
vention, and in what manner the same was to be performed, and
cause the same to be filed in the Great Seal Patent Office within six
calendar months next and immediately after the date of the said
Letters Patent.
NOW KNOW YE, that I, the said Michael Kennedy, do hereby declare

page_text: performed, to be particularly described and ascertained in and by the
following statement, reference being had to the accompanying Drawings,
and to the letters and figures marked thereon, that is to say :-
My said Invention has for its object the increasing the accuracy of
weighing scales, and consists as follows:-
Firstly. In the improved form and construction of the "adjusters"
for the different levers.
Secondly. In so constructing the connecting rods which unite the
different levers that the said levers can be united the one to the other
without displacing the pivots when adjusting the said connecting rods
in their places.
Thirdly. In the transmission, when necessary, of the effect of the
weight by tension and compression simultaneously, and in the con-
struction of connecting rods designed for this purpose.
Fourthly. In the formation of shoulders on each pivot of the several
levers.
And in order that my said Invention may be fully understood I shall
now proceed more particularly to describe the same, and for that purpose
shall refer to the several Figures on the annexed Sheets of Drawings,
the same letters of reference indicating corresponding parts in all the
corresponding Figures.
Sheet 1 of my Drawings illustrates the various parts or details
detached with my improvements applied thereto.
Figure 1 on Sheet 2 of my Drawings represents a plan, Figure 2 a
front view or clevation, and Figure 3 a side view or elevation of a short
levers weighing scale with all the essential parts constituting my
improvements in their respective places.
Figure 1 on Sheet 3 of my Drawings represents a sectional elevation
on a smaller scale of my improved short levers weighing scale complete;
Figure 2 is a plan of the same showing one portion of the platform in
its place, and the other portion removed; and Figure 3 is a transverse
vertical section taken along the line A, B, in Figure 2.
Before proceeding to describe the various essential features or heads
of my Invention, 1 will here indicate that which I consider to be the
best arrangement of the fulcrum pivots of the levers and their supports,

page_text: but to which arrangement I lay no claim as forming any part of my
Invention.
The working of the lever is effected by three pivots, slicwn in Figures
A and X (Sheet 1), namely, the pivot a, which supports the lever, and
is therefore called the fulcrum pivot; the pivot b, which is designed-to
receive the effect of the weight cither from the platform of the machine
or from another lever, and is called the pivot of resistance or of the
short arm of the lever; and the pivot c, placed in an especial piece
designed to adjust the levers and therefore called the pivot of the
adjuster. The pivot edges of these three pivots must be placed in such
a position that by uniting the said edges by three right lines, that is to
say, by drawing a first right line from the edge of the pivot c of the
adjuster (Figure X) to the edge of the fulcrum pivot a, a second right
line from the edge of the fulcrum pivot a to the edge of the pivot b
of the short arm of the lever, and a third right line from the edgo
of this last pivot to the edge of the pivot c of the adjuster,
a right-angled triangle is obtained of which the right angle is. at the.
edge of the fulcrum pivot a (Figure X). But the position of the pivots
established on this. principle alone is far from rendering the machine
perfect, indeed under the pressure of the weight the lever has a tendency
to slip on the cushion or bearing which supports it by its fulcrum pivot,
so that the machine will either not weigh at all or will give an incorrect
weight. In order to remedy this grave defect it is necessary to give the
fulcrum pivot a an inclination which corresponds with the direction of
the pressure of the weight, and that the support of the lever, either by
its cushion or bearing or by its branches, should have an inclination
similar to that given to the fulcrum pivot. To find this inclination,
which must be given to the fulcrum pivot and to the support of the
lever, it is necessary to construct upon the hypothenuse of the right-
angled triangle above described an equivalent triangle c, b, d, (Figure X),
so as to obtain a parallelogram, and the diagonal d, a, drawn from the
angle of the edge of the fulcrum pivot a indicates the inclination
which it is necessary to give to this last-named pivot as well as to its
support.
Sheet 1 shews the different supports of the levers with the inclination
above indicated, namely:-Figure F represents the support of a first
lever; Figure K represents the support of a second lever; Figure R
represents the support of a lever with equal arms;. Figure S represents

page_text: the support of the beam lever, Figure D. As to the support. (Figure P)
of the beam lever, Figure E, instead of giving the inclination to the
support itself, I have given it to the cushion or bearing which it holds;
thus, I cut the said cushion or bearing in such a manner as to form
in its centre, which comes in contact with the pivot of the lever, an
angle which corresponds with the inclination of this last.
I shall now proceed to describe the first head of my Invention, namely,
the improved form and construction of the "adjusters" for the different
levers. Whatever care is used in manufacturing the levers it is impossible
to make them with complete exactness in such a way that the arms of
the levers of the same catagory once furnished with their pivots shall
have the mathematical exactness which is necessary to render the
machine perfect. Ience the necessity of employing the part known as
the "adjuster" on account of the use to which it is applied. This
piece, which makes a part of the combination of the lever, carries one of
its pivots, and its form and construction permit of the shortening or
lengthening of the arm of the lever of which it makes a part in such a
way that when the machine is once set up all the levers can be adjusted
one with the other with the most complete exactness.
As the construction of the improved "adjuster" varies according to
the nature of the lever to which it is attached, I may observe before
describing it that there are various kinds of levers employed in these
machines, videlicet:-
1. Levers which are called first levers, because they first receive the
impression of the weight placed upon the platform of the machine (sec
Figure A, Sheet. 1). Every weighing machine has a greater or less number
of these according to its size.
2. Levers called second levers (see Figure B, Sheet 1), because they
receive the effect of the weight from the first levers.
3. Levers called beam levers (see Figures D and E, Sheet 1), because
they transmit the effect of the weight to the weighing beam. These
last-mentioned levers are of two kinds, ono (Figure E, Sheet 1) which is
employed when the weight is to be transmitted directly from the second
lovers to the beam lever, and the other (Figure D, Sheet 1) when the
lever called the lever with equal arms is employed to transmit the weight
from the second levers first to this lever with equal arms, and thence
to the beam lever which conveys it to the weighing beam itself.

page_text: 4. Levers called levers with equal arms (Figure C, Sheet 1), because
as their name implies the length of their two arms is always equal, and
they only serve to transmit the effect of the weight as they receive it.
The employment of the "adjuster" has necessitated naturally some
changes in the construction of these different levers, therefore I shall
speak of these last at the same time as I describe the peculiar con-
struction or form of my improved "adjuster" which specially belongs to
them.
The first lever (Figure A) is formed of one piece of cast iron varying in
thickness, furnished with two cars in designed to strengthen the fulcrum
pivot; it is solid below, but is soon divided into two branches », which leave
between them a space e designed to allow of the passage of another
piece herein-after referred to. In their upper part these two branches
are united by a casting, which at the same time forms a projection o
forward (Figure A). This projection is designed especially to receive
in a hole made there the rod of the adjustor which now occupies it.
Departing from this same junction the two branches of the body of the
lever approach each other, rise parallel the one to the other, and their
surfaces upon which certain parts of the adjuster are to slide must be
made in such a way that this last in its movements ascending or
descending shall always maintain the pivot which it carries in the
geometric position above described. In the lower and solid portion of
the lever two holes are reserved, which pierce it transversally and aro
designed to receive each a pivot. Between these two holes an opening g
is made (Figure A) designed to allow foreign matter to escape from the
lever, such as water or other matter, which without this opening would
accumulate and prevent the free working of the scale, and deteriorate
it, among others, by the rust which would there be formed. The
improved form of "adjuster" which I use for these first levers is com-
posed of two parts and two nuts. The upper part is one casting, of
which the lower part (Figure A) has the form of a half circle which
terminates by two upper parallel branches or jaws p. The thickness of
these two branches or jaws corresponds with the thickness of the branches
of the lever, and the space comprised between these two branches or
jaws must correspond also with the space left between the two said
branches of the lever upon which the improved adjuster is applied.
These two branches or jaws of the adjuster are united by a small casting
designed to strengthen the pivot carried by the adjuster, and each of

page_text: them is provided with a hole designed to receive the third pivot, or pivot
of the adjuster. This upper part of the adjuster on each side, abovo
and below, is furnished with castings or guidest cast with it. These
guides are designed by sliding along the branches of the lever to
maintain the adjuster in a given position, in order that the pivot which
it carries may be always on the right line of the angle, as has been
explained. At the lower portion of the half circle at a point which
must correspond exactly with the hole reserved for that purpose in the
projection of the lever is found the second parts of the adjuster, that is
to say, an iron rod, which is placed in the mould when the upper part of
tho adjuster is cast in order to make a whole perfectly united and
consolidated. This iron rod traverses the hole reserved in the projection
of the lever, to which it is fixed by two nuts, one above and one below
this projection. These two nuts serve at the same time to work the
adjuster. As to the second levers (Figure B, Sheet 1), I make their
upper part according to the indications which I have just given for the
first levers, and the construction of the adjuster is made on the same
plan as that of the adjuster of the first levers. As to the beam lever
(Figure E, Sheet 1), used to transmit the effect of the weight from the
second levers to the weighing beam itself, it is composed of one solid
casting a (Figure E), which is hollow only in the part which forms the
short arm of the lever. On the side of the opposite extremity of this
casting is a casting c projecting outwards; lower down is a second
casting d like the one above. These two castings cast with the principal
piece form with it but one body; each of them is pierced with a hole
designed to receive the rod of the adjuster. In this beam lever the
improved adjuster is composed of a head e in form of a fork with two
branches or jaws; each branch is pierced with a hole designed to receive
the pivot which they are to carry, and these two branches or jaws are
also united by a casting designed to strengthen the said pivot. At the
lower part of this head is an iron rod stronger than the rod of the
adjuster of the first lovers. This rod of the adjuster of this beam lever
traverses the two holes of the castings c and d above indicated; it is
also fixed and worked by two nuts placed one above and the other
below the lower casting. As to the beam lever (Figure D) employed in
case the lever with equal arms is used, it is constructed on the same
principles as the second levers, and its adjuster is like that of these Inst.
As to the lever with equal arms (Figure C) which is employed to change
the direction of the transmission of weight, it only differs as to the

page_text: principles of its construction from the first levers in its peculiar form
of adjuster; thus the casting which in the first lever unites its two
upper branches and forms a projection o forward (Figure A) to be
traversed by the rod of the adjuster, in the lever with equal arms this
casting (Figure C) is placed on the side opposite to that which is
occupied in the first lever, a change made necessary by the small length
of the arm of the lever, which does not leave sufficient room for the play
of the nuts. As a consequence another casting a starts from the upper
casting of the adjuster between the two lower guides c, c, traverses the.
two branches of the lever, and is prolonged backward till it comes above
the casting o described above. To this casting a there is secured an
iron rod i which traverses the hole of the lower casting o, where it is
fixed and worked by two nuts.
As to the second head of my Invention, namely, the so constructing
the connecting rods which unite the different levers that the said levers
can be united the one to the other without displacing the pivots when
adjusting the said connecting rods in their places. These connecting
rods are of the following categories, videlicet:-
1. The connecting rod which transmits the effect of the weight from
one to another of the first levers, and from them to the second levers.
2. The connecting rod which transmits the effect of the weight from
the second levers to the beam lever when this last is placed between the
two second levers.
3. The connecting rod which transmits the effect of the weight from
the second levers to the lever with equal arms when this is placed
between the two second levers.
4. The connecting rod which transmits the effect of the weight from
the lever with equal arms to the beam lever.
5. The connecting rod which transmits the effect of the weight from
the second levers either to the beam lever or to the lever with equal
arms when this beam lever or this lever with equal arms is placed out-
side of the frame of the scale.
As regards connecting rods which transmit the effect of the weight
from one to another of the first levers, and from them to the second
levers. There is in every scale one of these connecting rods for every
second lever. Each connecting rod transfers the effect of the weight

page_text: the
from all the first levers which are in a right line with a second lever to
this second lever, transferring first the effect of the weight from the
first lever the most distant to the next first lever, and from the first to
the second lever. Each connecting rod is attached to the long arm
of the first levers, which it puts in communication with each other and
terminates at the short arm of the second lever. Commencing at the
first lever, the furthest removed from one of the second levers in the
same right line, such connecting rod is composed at its point of depar-
ture, which I call the head of the connecting rod (shown at N', Figure
N) of a bar of round iron, which I bend at its centre, widening it at this
point till it seizes between its two branches N'; a, a cushion or
bearing by the three grooves of this last, which are cut in the same
direction, the back of the cushion or bearing, that is to say, groove
opposite to the sides of the cushion or bearing designed to receive the
pivot of the adjuster of the first lever, resting against the inner side of
the curve of the said har of iron. As soon as the two branches N', a, of
this said curved bar of iron leave the cushion or bearing placed between
them they are brought nearer one to the other sufliciently to prevent
the said cushion or bearing from leaving the position which it occupies,
while at the same time permitting a slight movement in its grooves.
Each of the two extremities of this bar of iron terminate in a ring b
formed in the direction of the groove of the cushion or bearing destined
to receive the pivot, and these two rings preserve between them a suffi-
cient space to let a third ring d of another bar of iron N", which will
be spoken of hereafter, to be placed in this space.
is
Before describing the part of the connecting rod which serves to unito
this first part or head of the connecting rod of which we have just been
speaking to a third part destined to receive the pivot of the adjuster of
the first lever next following I shall describe at once this third part. This
third part N of the counecting rod, which I call the part in common,
formed of a round bar of iron. It is equally bent at its centre, leaving
at the point of the curvature a space destined to give passage to one
of the extremities of the bar of iron forming the second part or inter-
mediate portion N" of the connecting rod, which extremity is terminated
by a ring. At an inch and a half about from the inner centre of this
curvature a piece of iron p is grasped firmly by the two bent branches.
This piece of iron, which is to serve as a support to the cushions or
bearing, has its side which is to touch the said cushion or bearing

page_text: rounded to correspond with the groove of this last. This piece of iron
once fixed the cushion or bearing is placed as for the first part of the
connecting rod to which I have always referred which is similarly pressed
by the two branches o terminating also in rings q.
Returning now to the second part N" of the connecting rod, which I
call the intermediate part, I may observe that this is formed of a round
bar of iron N" of which the length varies naturally, according to the
distance which separates the two levers which it is to unite. One of the
extremities of this bar passes into the third or common part of the con-
necting rod at the place that has been reserved for this purpose, and
which it surrounds, forming there its ring. Its other extremity
terminates in a ring & destined to be placed between the two rings b, b,
which terminate the first part of the connecting rod.. A. bolt unites
these three rings.
Passing now to the part N of the connecting rod which receives
the cushion or bearing destined to bear against the pivot of the short arm
of the second lever, which part of the connecting rod may be considered
as the termination of the connecting rod, and which I am now about to
describe, I may observe that this last part N is made like the first
part N or head of the connecting rod, but when once placed it occupies
not only a position inverse to the first part, that is to say, that the
upper part of the cushion or bearing & which is fitted there as well as
the two rings g which terminate the part N are turned towards the
upper part of the cushion or bearing and towards the two rings 6 of
this first part, but also while the surface or upper part of the cushion or
bearing n of the first part is horizontal the surface or upper part of the
cushion or bearing K of the last part is vertical. Between this last part
or termination N""" of the connecting rod and its third part N", which
I have called the common part, there is also an intermediate part N""".
This intermediate part is composed of a bar of iron of which the length
is also in proportion to the distance which separates the two levers which
it unites. Each extremity of this bar terminates also in a ring x, 2,
respectively, but formed in a direction opposite the one to the other, that
is to say, that while one ring 3, namely the one brought near the second
lever, is vertical, the other ring x, namely the one near the first lever,
is horizontal, an arrangement made necessary by the different positions
occupied by the two parts of the connecting rod which this intermediate
part unites. Each one of these extremities forming rings are placed, the

page_text: one 2 between the two rings q which terminate the third part or part in
common, and the other between the two rings q which terminate the
last part or termination of the connecting rod. In the two cases cach
extremity is united to the two rings by a bolt. In case the scales on
account of its length requires the employment of more than two first
levers on each of its sides the connecting rod of which I have just.
spoken has the same arrangement at its first part or head and at its
last part or termination N. For each of the supplementary first levers
I employ a portion of connecting rod like that which I have described
under the name of third part or part in common N", and the
intermediate part of the connecting rod which unites the first levers is
like the second part or intermediate part N" before described.
The connecting rods of the second and third category before referred
to, while participating in the improvement which occupies us at this
moment, enter more especially into the fourth head of my Invention, and
I will hereafter speak of them while treating of the improvement making
the object of this head of Invention. As regards the connecting rod
which transmits the effect of the weight from the lever with signal arms
to the beam lever, and which is herein-before referred to as coming
under the fourth category. The two extremities of this connecting rod
are alike the one to the other, and each is constructed like the head N'
of the connecting rod (Figure N) of the first levers. Only these two
extremities once placed find themselves face to face, and in different
directions, the cushion or bearing adhering to that extremity which is in
contact with the lever with equal arms having its upper part vertical,
and the cushion or bearing adhering to the extremity which is in contact
with the beam lever having its upper part horizontal. As to the
intermediate part which unites these two extremities it is like the
intermediate part which unites the first lovers. As regards the con-
necting rod which transmits the effect of the weight from the second lever
either to a lever with equal arms or to a beam lever when one of these
last is placed outside of the frame, and which was herein-before referred
to under the fifth category. This connecting rod, which extends from
one second lever to the other, and from there either to the beam lever
or to the lever with equal arms according as the one or the other is
employed, is like the connecting rod (Figure N) described before, which
extends from one of the first levers, traversing and being connected to
another first lever, and terminating at a second lever.

page_text: In terminating the description of the connecting rods above-mentioned,
I will particularly call attention to the importance of the idea which I
have rendered practical of dividing each connecting rod into several parts.
This division, of which I have just given one of the means of application,
alone permits the placing of the connecting rod where the lever is in its
position without the necessity of withdrawing the pivots to give passage
to the connecting rod, and of replacing the said pivot when the cou-
necting rod is in place. It alone permits also the formation in the levers
of a casting cast with the lever and destined to strengthen the pivot.
As to the third head of my Invention, namely, the transmission when
necessary of the effect of the weight by tension and compression simul-
taneously and in the construction of connecting rods designed for this
purpose. This transmission takes place when the beam lever is placed
in the frame of the scale between the two second levers, or when wishing
to change the direction of the transmission of the weight I employ
a lever with equal arms, which I place between the two second levers
in the frame of the scale. Indeed one of the arms of the lever
employed (the short arm in the beam lever when this is used) being
then placed in line with the long arms of the two second levers and
between them, it follows that the effect of the weight makes itself felt
on the beam lever in two different ways from one side, the right side for
example, looking at the front of the scale. The effect of the weight
makes itself felt on the beam lever by the tension of the part of the
connecting rod comprised between this beam lever and the second lever
placed at the right, while on the other or left side the effect of the weight
makes itself felt in an inverse direction, that is to say, by a pressure
which is directed from the second lever at the left to the beam lever,
and which makes itself felt upon the portion of the connecting rod
comprised between these two levers. This double effect of the weight
in contrary directions has necessitated as a consequence a difference in
the construction of the different portions of the connecting rod. I had
to find a way of replacing the bar of iron which ordinarily composes
the connecting rod by a piece which could resist the pressure of the
weight without being susceptible to the least deflection, which would
render the scale inaccurate. Thus I have formed of a tube instead of
a bar of iron this portion of the connecting rod which receives the
pressure. This explained I will describe the connecting rods of the
second and third categories before referred to, which while being

page_text: this tube to the pivot of the
This piece of iron terminates
divided like the preceeding more especially pertain to the fourth head
of my Invention which I am now describing. As to the connecting
rod which transmits the effect of the weight from the second levers to
the beam lever when this last is placed between the two second levers.
This connecting rod is composed then of a tube M', a, (Figure M) of a
length which varies according to the distance which separates the
second lever at the left from the beam lever. Each extremity of this
tube is cut like a screw on the exterior. At the left extremity of this
tube is a piece of iron destined to bind
long arm of the second lever at the left.
on one side in the form of a fork with two branches c, c, leaving
between these two branches an opening destined to receive a cushion
or bearing d. This cushion or bearing once placed in the fork of the
piece of iron the two branches are slightly bent over upon the cushion
or bearing to maintain it in its place. The side of this piece of iron
opposite to this opening is terminated by a short stud or holt b, of
which the circumference corresponds to the exterior circumference of
the tube a to which it is applied. It is cut like a screw, and once in
position it is fixed by means of a coupling piece e to the tube, of which
it thus becomes one of the extremities. The other extremity of the
tube, also cut like a screw, is destined to be united by means of another
coupling piece to another portion of the connecting rod, which I shall
now describe. This other portion M" of the connecting rod which encloses
the cushion or bearing which is to be in contact with the pivot of the
short arm of the beam lever is composed of a round bar of iron, which
is bent at its centre until it grasps by its two branches i, i, the cushion
or bearing which it is to hold, as and observing the same rules as for
the head N' of the connecting rod (Figure N) of the first levers pre-
viously described. These two branches terminate also in two rings h
as in the portion above mentioned. A prolongation is welded to
the exterior of this bar of iron at its point of curvature of a circum-
ference equal to that of the tube a, to which it is destined to be applied.
This prolongation is cut like a screw similar to the extremity of the
tube, to which it is also fixed by a piece of coupling. The tube having
at its left extremity the upper groove of the cushion or bearing d which
is to be in contact with the pivot of the long arm of the second lever
placed in a vertical direction, this second portion having become the
right extremity of the tube, must be placed in such a way that the
upper groove of the cushion or bearing which it carries is horizontal.
!!

page_text: This same connecting rod (Figure M) is composed of two other portions,
one which may be considered as the extremity M"" of the connecting
rod, the tube at the left M', a, being its commencement; it is destined to
be in contact by its cushion or bearing with the pivot of the long arm
of the second lever at the right, and is like the portion N of the con-
necting rod (Figure N) previously described as the head of the con-
necting rod of the first levers. This final portion or termination of the
connecting rod to which I am now referring has its bend turned towards
the exterior of the scale, that is to say, in such a way that the upper
side of the cushion or bearing which it carries and which is destined
to receive the pivot of the long arm of the second lever at the right
of the scale is turned towards the side of the part in common M" of
the connecting rod (Figure M) or of the beam lever, the cushion or
bearing of this part in common and the cushion or bearing of the
termination of the connecting rod being thus face to face. The upper
groove of the cushion or bearing of the right is placed on the same
plane as the upper groove of the cushion or bearing of the left.
Finally the portion M" of this connecting rod which remains for me
to describe is the intermediate which unites the right extremity M""" or
termination of the connecting rod to its part in common M". This
intermediate portion is composed of a bar of iron, and is like the inter-
mediate portion N'" (Figure N) described above as being placed between
the last first lever and the second lever. As regards the connecting
rod which which transmit the effect of the weight from the second
levers to the lever with equal arms when this is placed between the two
second levers, and which has been hercin-before referred to as coming
under the third category. This consists of the same connecting rod
as that previously described (Figure M) for the transmission of the
weight from the second levers to the beam lever placed in the same
position, with this. single difference, that the three cushions or bearings
which it carries have each their upper side in a vertical direction.
As to the fourth head of my Invention, namely, the formation of
shoulders on each pivot of the several levers, I form to each pivot of
all the levers indiscriminately two shoulders with the very important
aim of preventing all contact of the cushions or bearings with any
part of the cast iron of the levers. The fulcrum pivots have their two
shoulders at the points a where they come out of the lever (Figure (),
and the pivots of the short arms as well as the pivots of the long arms

page_text: of the levers have their two shoulders a' within the lever (see Figure O').
To prevent also all contact of the cushions or bearings with the
lever, augmenting by this means still more the precision and durability
of the scale, I make in the form of a point a (Figure T) the two
sides of each cushion or bearing which would come in contact with
the lever.
Having thus described especially all the pieces in which my Invention
consists I shall now proceed to describe the mode of erecting a scale
furnished with these same pieces.
After having constructed a foundation sufficiently firm to support
my scale and the weight which it will have to weigh, and reserved
between the foundations a space sufficient for the placing and the
play of the pieces which compose it, as is done in erecting every
scale, I take the supports F (Sheet 11) Figure F, Sheet 1, of the first
levers, which I place on a horizontal plane at four points, forming right
angles, and more or less separated according as I desire a scale with
a platform larger or smaller. Each one of the supports should by
preference have its inclination directed in the direction opposite to
the place to be occupied by the second levers. I then take four plates
or lower yokes G (Sheet 11) and Figure G (Sheet 1), I bind them
two by two transversely to the said plates by means of two beams
of wood or metal, which I attach with screws upon the surface of the
two extremities g of each plate destined to receive them. These pieces
of wood must have a height sufficient that there may be between the
platform which is fitted or placed upon them and the upper extremity of
the first levers sufficient space for the free play of these last. But on
account of this height the upper part of these beams are then on a
plane more clevated than the plane which the connecting rods must
follow, and these running in a transverse direction to the beams notches
sufficiently large to permit the free passage of the connecting rods
are made in cach one of these beams at the places where the connecting
rods are to pass. In binding together my two plates or lower yokes G
I observe that the distance left between them from centre to centre
shall be the same as that which I have left between my first levers
equally from centre to centre, in such a way that when I shall suspend
by the aid of the oval links I, Figure 3, Sheet 2 and (Figure I, Sheet I.)
the plates G to their respective upper yokes L, Sheet 2, and Figure L,
Sheet 1, the looks of the plates G shall correspond exactly with the

page_text: hooks of the upper yokes L. My four plates once bound in this way
two by two I place two of these plates bound together over the
supports F, F, (Sheet 11) of the two first levers the furthest removed
from the second levers, making each of these supports pass through
the empty space a which is in the middle of the plate or lower yoke G.
I then place in the same manner my two other plates bound together
over the supports F of the first lever (Sheet 11) which are the nearest
to the two second levers. I then take my four first levers, Figure A,
Sheet 1, and A, Sheet 11, which I place on their respective supports
in such a way that the edge of the pivot of the adjuster is turned to
the side opposite the place where the second levers are to be. I then
introduce an upper yoke, Figure L (Sheet 1) and L (Sheet 11) into
each of these levers, and I take the links, Figure I (Sheet 1) and I
(Sheet 11), which I suspend on the hooks of my yokes. I then take
two supports, Figure K (Sheet 1) and K (Slicet 11) of the second
levers, I fix them on the vertical surface of a piece of wood placed
to receive them. I place them in such a way that once in position
the pivots of their second levers are on a vertical planc, the bevelled
side a (Figure B, Sheet 1) of the fulcrum pivot is below, resting on the
steel button » (Figure K), and in such a way that when I unite the
long arms of the first levers to the short arms of the second levers.
by means of the connecting rod this preserves perfectly its right line
and its horizontal position.
Passing to my beam lever, Figure E (Sheet 1) and E (Sheet 11), and
supposing this placed between my two second levers, I fix its support,
Figure P (Sheet 1) and P (Sheet 11), by means of screws or of bolts upon
a piece of wood prepared for this purpose; the surface of this piece of
wood must be not only vertical with respect to the earth, but also
following a perpendicular plane forming a right angle with the vertical
surface on which are fixed the supports of the second levers. I fix the
support of the beam lever in such a way that in placing this its fulcrum
pivot and the pivot of its long arm are in a horizontal plane lower than
the horizontal plane of the connecting rods of the first levers by the
entire length of the short arm of the said beam lever; thus this will be
placed horizontally, its pivots being also in horizontal planes. The
connecting rod, Figure M (Sheet 1) and M (Sheet 11), which unite the
long arms of the two second levers to the short arm of the beam lever
must follow a perfectly right line perpendicular to the two lines which

page_text: the connecting rods N follow, shown at Figure N (Sheet 1), and also on
Shect 11, which rods attach the first levers to each other and then to the
second levers, and in the same horizontal plane. As to the weighing
beam I effect the transmission of the weight to it as in every scale by
means of a connecting rod W (Figure 2, Sheet II) of which the lower
extremity is attached to the long arm of the beam lever. I fix two pieces
of wood or columns of a suitable height above the beam lever. These
two columns are united at their upper part by a capital, to which I fix a
hook from which the weighing beam is to be suspended by its fulcrum
pivot in such a way that the pivot of its short arm shall be in a
perpendicular, line drawn from this point to the pivot of the long arm
of the beam lever. My pieces once thus arranged I unite my levers by
the different connecting rods which belong to them. I suspend my four
plates G to their respective yokes by the aid of the links with which 1
have been careful to provide these last. I apply with care the groove
which exists in the lower centre of the yokes to the pivots a. (Figure L,
Sheet 1) of the short arms of the first levers. I then fit my flooring or
platform on the beams which unite the plates of the first levers, after
which I regulate my scale with the aid of the adjusters with which
each lever is furnished, and the scale is ready to weigh.
The working of my scale operates in the following. manner :-A
weight placed on the platform is transmitted directly to the short arms
of the first levers, which in their turn transmit the effect of the weight
to the second levers, but the weight transmitted to the short arms of
these last is diminished in the proportion of the difference of length
which exists in the two arms of the first levers. The second levers
transmit in their turn to the beam lever by their long arms the effect
of the weight which they have received, but this weight already.
diminished a first time is still once more reduced according to the
proportion of the difference of length which exists between the two arms
of the second levers. In its turn the beam lever transmits the effect of
the weight to the weighing. beam itself (shewn in Figure 1, on Sheet 3 of
the Drawings), which weight, on arriving at the weighing beam, is still
further diminished in the proportion of the difference which exists in
the length of the two arms of the beam lever. From this it results
that if I give to the long arm of the weighing beam itself a length
proportionate to its short. arm as 12 is to 1, if I make the arms of the
beam lever as 6 is to 1, the arms of the second levers as 3 is to 1, and

page_text: the arms of the first levers as 4 is to 1, a weight of one pound placed
at the extremity of the long arm of the weighing beam will represent a
weight of nine hundred and seventy-two pounds on the platform.
Having now described and particularly ascertained the nature of my.
said Invention, and the manner in which the same is or may be used
or carried into effect, I would observe in conclusion that what I consider.
to be novel and original, and therefore claim as the Invention secured
to me by the hercin-before in part recited Letters Patent is,―
First. The peculiar form or construction of the adjusting piece and
its jaws and the mode of applying the same to the levers, substantially.
as and for the purpose herein-before described and illustrated by my
Drawings.
Second. The constructing of the connecting rods in different portions,
whereby the several levers can be connected together without the
necessity for displacing the pivots upon adapting the connecting rods
thereto.
Third. The transmission of the effect of the weight both by tension
and by compression simultaneously when necessary, and the construction
of the connecting rods relating thereto, substantially as and for the
purpose herein-before described.
Fourth. The formation of shoulders on each pivot of the lovers, for the
purpose herein-before described.
In witness whereof, I, the said Michael Kennedy, have to this
my Specification set my hand and seal, this Third day of
November One thousand eight hundred and sixty-nine.
MICHAEL KENNEDY
ATCHA ETL KRNIV
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