IMPROVEMENTS IN THE CONSTRUCTION OF WEIGHING MACHINES AND WEIGH BRIDGES."
Year: 1862

page_text: LETTERS PATENT to Henry Pooley, junior, of the Firm of Henry Pooley
and Son, of Liverpool, Engineer, for the Invention of "IMPROVEMENTS IN
THE CONSTRUCTION OF WEIGHING MACHINES AND WEIGH BRIDGES."
PROVISIONAL SPECIFICATION left by the said Henry Pooley at the
Office of the Commissioners of Patents, with his Petition, on the 31st
March 1862.
I, HENRY POOLEY, junior, of the Firm of Henry Pooley and Son, of
Liverpool, Engineer, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN THE CONSTRUCTION OF WEIGHING MACHINES AND WEIGH
BRIDGES," to be as follows:-
This Invention relates to improvements upon that part of the weighing
machines and weigh bridges called the steelyard or weigh beam. In the
improved machinery, by means of a compound poise or travelling weight I
dispense altogether with the loose weights representing tons or hundredweights,
as the case may be, and which in the ordinary weighing machine are placed
on a counterpoise or scale depending from a knife edge, which is immoveably
fixed into the extremity of the long arm of the steelyard; I also by a virtual.
elongation of the weigh beam secure a command over the balance never before
attained. The poise consists of three principal. parts, namely, the weight

page_text: itself, a supplementary steelyard secured to its side, and a revolving weight.
The compound poise is moved back and forth by a handle, and secured in
position by a jointed catch which drops into serrated divisions cut into the
The
upper edge of the steelyard, and representing tons or portions of tons.
revolving weight is cylindrical and is free to turn on its spindle, which is
carried by brackets projecting from a hollow sliding weight. On the cylin-
drical weight a worm or screw thread is formed, which takes into a rack
formed by diagonal divisions cut on the upper edge of a supplementary steel-
yard which is attached to and forms a part of the poise or shifting weight
above described. The divisions on this supplementary steelyard represent cwt.
or the larger fractional parts of the tons or larger divisions cut on the main
bar of the steelyard. A pointer attached to the hollow sliding weight which
carries the cylinder points to these large fractional parts. To facilitate the
rapid movement of this weight, portion of the thread turned on the cylinder is
notched or planed out to disengage it from the rack teeth, and allow of its
being slidden along freely. The periphery of the cylinder is graduated to the
lowest fractional parts of the load to be weighed, which are indicated in use
by a pointer. To ensure nice adjustment the long arm of the steelyard is
slotted to receive within it a brass or other metal slide, which is retained in its
place by covering plates at each side, from which project laterally knife edges
to receive the shackle of a hollow counterweight. The slide is bored longi-
tudinally and tapped to receive a screw for traversing it in its slot. The
hollow weight is fitted with a screwed plug, which may be removed for the
purpose of loading or unloading the weight as may be found needful. By the
use of this adjustable counterbalance much trouble and uncertainty in adjusting
the machine are avoided, as the screw, which is of a fine pitch, enables the user
to arrive at a perfect balance with ease and rapidity.
:
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Henry Pooley in the Great Seal Patent Office on the 30th,
September 1862.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I; HENRY
POOLEY, junior, of the Firm of Henry Pooley and Son, of Liverpool, Engineer,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letter's
Patent, bearing date the Thirty-first day of March, in the year of our Lord
One thousand eight hundred and sixty-two, in the twenty-fifth year of Her

page_text: reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said Henry Pooley, Her special license that I, the said Henry Pooley, my
executors, administrators, and assigns, or such others as I, the said Henry
Pooley, my executors, administrators, and 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, use, exercise, and
vend, within the United Kingdom of Great Britain and Ireland, the Channel
Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN THE CON-
STRUCTION OF WEIGHING MACHINES AND WEIGH BRIDGES," upon the condition
(amongst others) that I, the said Henry Pooley, by an instrument in writing
my hand and seal, should particularly describe and ascertain the nature
of the said Invention, 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.
under
NOW KNOW YE, that I, the said Henry Pooley, do hereby declare
the nature of my said Invention; and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement, reference being had to the Drawing hereunto annexed, and to the
letters and figures marked thereon, (that is to say):-
My Invention relates to improvements upon that part of weighing machines
and weigh bridges termed the steelyard or weigh beam. In the improved
machines, by means of a compound poise or travelling weight I firstly dispense
altogether with the loose weights representing tons or hundredweights, as the
case may be, and which in many of the ordinary weighing machines are
placed on a counterpoise scale depending from a knife edge, which knife edge
is immoveably fixed into the extremity of the long arm of the steelyard; and
secondly, by a peculiar arrangement virtually elongate or contract the said
long arm of the steelyard, by which I secure a command over the balance
never before attained either in range or permanency.
Firstly, as respects the compound poise in the accompanying Drawing,
Fig. 1 is a side elevation of my improved steelyard, and Fig. 2 represents the
same in plan view. A, A, is the poise, which is freely moveable to and fro
along the steelyard, and is capable of being locked at any required position.
The poise consists of three principal parts, namely, first the weight itself, a
graduated bar B, B, secured by studs and bolts b, b, to the side of the weight,
and a revolving cylindrical weight C, C; D, D, is a bandle for moving the
poise and its appendages back and forth on the steelyard'; E, E, is a catch
jointed to the compound poise A, and intended to drop into any of the notched

page_text: graduations cut in the upper edge of the steelyard, and representing tons or
portions of, tons, for the purpose of retaining the poise in position. I prefer
divisions of the form shewn in the Drawing, but I do not confine myself.
thereto. The cylindrical weight C, C, is free to turn on its spindle or axis;
which spindle is carried by brackets F, F, projecting from the sliding weight.
G, G, which is itself carried by the graduated bar B, as shewn in end view in
the cross section of the steelyard, Fig. 3; this sliding weight G, G; is made.
hollow for convenience of primary adjustment. The weight G is capable of
sliding on the graduated bar B. Fitted to or cut on the cylindrical weight C.
is a V-shaped worm or screw thread, which takes into the diagonal notched
graduations cut on the upper edge of the graduated bar. These diagonal'
notches are cut so as to form divisions or graduations representing, hundred-
weights or the large fractional parts of the tons or other large divisions cut on.
the steelyard. Between the brackets F and attached to the sliding weight G.
stands a pointer d; for indicating on the graduated bar B the larger fractional
parts of the loal being weighed. To expedite the movement of the weight a
portion of the worm or screw thread of the cylinder is notched or planed out,
as shewn at c, Fig. 3; this notch must be of a width at least equal to the
thickness of the bar B, in order to disengage the thread of the cylinder from
the notched graduation, and allow of the weight G being moved freely over
the graduated bar.
To one of the brackets F, I attach a pointer. e, which lies parallel with the
axis of the cylindrical weight C, and points to a graduated ring or belt on.
the periphery of that cylinder, the divisions in which ring or belt represent.
the lowest fractional parts of the load to be weighed.
The following is the mode of using the steelyard:-When a load is to be
weighed the compound poise is moved along the steelyard as far as is needful
to indicate the main portion of the load; the cylinder C and its carriage are
then slidden. along the graduated bar to indicate the larger fractions of the
divisions on the steelyard; then by turning the cylinder till the load to be
weighed is nicely balanced, the minute fractions are indicated by the pointer
e, e, the whole weight is then read off with facility at a glance, and without
the possibility of error.
For ease of manipulation in the factory I prefer to make my weight A, A,
in halves, which when truly planed and surfaced to the beam, are put together
by bolts, but though I have thus represented it I do not wish it to be understood
that confine myself to this precise method, or the exact form shewn in the
Drawing, neither do I confine myself to the position or mode of attaching my
graduated bar to its carrying weight as represented in the Drawing. Secondly,

page_text: as respects this improved adjustment, to ensure nice adjustment of the machine
I slot the extremity of the steelyard in order that it may receive within it a
brass or metal slide, from which slide depends a counterpoise weight. The
mode of applying this improvement is shewn best at Figures 4 and 5, where
H is the slot; I, the metal slide; and J, the counterpoise weight. The slide
is retained in its place by the covering plates N at each side, from which
project laterally knife edges for receiving a shackle K, which receives the
suspending hook of the counterweight J. The slide I is bored horizontally
and parallel to the plane of the knife edges O, O, and P, P, (Figures 1 and 2)
of the steelyard, and tapped to receive a screw L, by turning which the slide
is traversed to and fro as required in the slot. The head of this screw L is
sunk flush with the extremity of the steelyard beam, and it is made to receive
a key, which being kept in the possession of the owner or his deputy, prevents
all tampering with the balance. The counterweight J, J, I make hollow,
and fit it with a screwed plug, which may be removed for the purpose of
increasing or reducing the weight as may be found needful. By the use of
this adjustable counterbalance much trouble and uncertainty in balancing the
machine are avoided, as the screw L, which is of a fine pitch, enables the user
to maintain a perfect balance with ease and rapidity, preserving its functions
without depreciation as long as the machine endures.
Having now set forth the nature of my Invention of "Improvements in the
Construction of Weighing Machines and Weigh Bridges," and explained the
manner of carrying the same into effect, I wish it to be understood that under
the above in part recited Letters Patent I claim,-
First, the compound poise constructed as above described, for shewing the
weight of a load to the fractional parts of the divisions of the steelyard.
And, secondly, the means above described whereby I am enabled to adjust
the balance of weigh beams.
In witness whereof, I, the said Henry Pooley, the younger, ha hereunto
set my hand and seal, this Twenty-ninth day of September, in the
year of our Lord One thousand eight hundred and sixty-two.
HENRY POOLEY, J³. (L.S.)