AN IMPROVED SCALE FOR WEIGHING LETTERS
Year: 1859

page_text: LETTERS PATENT to Thaddeus Fairbanks, of St. Johnsbury, in the
County of Caledonia, and State of Vermont, of the United States of
America, for the Invention of "AN IMPROVED SCALE FOR WEIGHING
LETTERS."
Sealed the 3rd February 1860, and dated the 17th December 1859.
COMPLETE SPECIFICATION filed by the said Thaddeus Fairbanks at the
Office of the Commissioners of Patents with his Petition and Decla-
ration, on the 17th December 1859, pursuant to the 9th Section of the
Patent Law Amendment Act, 1852.
TO ALL TO WHOM THESE PRESENTS SHALL COME, BE IT
KNOWN, that I, THADDEUS FAIRBANKS, of St. Johnsbury, in the County of
Caledonia, and State of Vermont, of the United States of America, have
invented "AN IMPROVED SCALE FOR WEIGHING LETTERS," and I do hereby
declare that the nature of the said Invention and the manner in which the
same is to be performed, or in other words, its construction and mode of
operation are fully described and represented in the following Specification,.
and the accompanying Drawings, of which Fig. 1 denotes a side elevation of
such scale; Fig. 2, a top view; Fig 3, a longitudinal and vertical section,
and Fig. 4, a transverse section, taken through the plate, its frame, and
pendulous weight.
In the Drawings A represents the foundation or base for supporting the
operative parts. From the said base part two vertical standards or columns
B, C, extend upward, and have mortises a, b, made respectively in their top

page_text: parts, the same being for the reception of a wedge or knife-shaped bar D,
whose ends c, d, rest respectively in the said mortises. The said bar D passes
transversely through the graduated arm E, and serves as a fulcrum for it,
such arm being provided with divisions to mark either the whole ounces or
fractions of the same, as shown in the Drawings. At or near the rear part of
the arm E, and over the same, as shown in the Drawings, a plate F is
suspended, such plate having a rectangular frame H attached to its under
side, as shown in Fig. 4. From the inner vertical sides of said frame ears or
projections h, i, extend, such being respectively recessed on their under sides
for the reception of the ends of a knife-edged bar I, which extends transversely
through the graduated arm and near to its rear end, as shown in Figure 4.
By means of the said projections and bar the plate is sustained and rendered
capable of being easily vibrated. To the middle of the lower part of the said
rectangular frame a rod I' is attached, extends downward through a hollow
column L, (which projects upward from the base or foundation, as shown in
the Drawings,) and has a weight K screwed or firmly affixed to its lower end,
such being for the purpose of preserving the plate E in a horizontal position
whatever may be the inclination of the said graduated arm. From the rear
part of the said hollow column a standard M extends upward, its top surface
serving as a bearing for the rear extremity of the graduated arm to rest
upon, when the upper and lower faces of the said graduated arm are in
horizontal planes, a loop or eye g passing around the rear extremity of the
arm serving to prevent it from receiving too great an inclination, or such as
would cause the poise N by its gravity to slide on the arm.
An apparatus constructed in the above described improved manner is very
convenient and useful for merchants and others, it being not only very simple
in construction, but very effective in operation.
I do not claim balancing a scale pan and weighing lever by means of a
pendulous weight applied to a straight arm extending downward from the
central part of the pan. Nor do I claim supporting a scale pan on the prongs
of a bifurcated steelyard, extending a rod or arm downward from the middle
of the pan, and jointing such rod at its lower end to an arm parallel to the
steelyard, and hung at its other end on a fulcrum situated immediately under
that of the steelyard. Nor do I claim under this latter construction the
application of a stop in front of and to the forked steelyard, so as to act in
concert with a stationary staple, or its equivalent.
In my construction of scale I make the weighing lever or steelyard without
any bifurcation or fork, but simply as a straight bar, provided with knife edges
for supporting the bearing of a pendulous weight, and such weight I hang

page_text: upon such knife edges by means of a forked rod furnished with bearings to
receive such knife edges. Furthermore, I extend the front end of the weighing
or steelyard lever into a stationary staple a arranged at the top of the post N,
as shown in the Drawings, such staple being made so as to allow the said
front end to play freely up and down a short distance. By my construction I
not only attain the advantages of the pendulous weight over the forked lever,
but I employ the weight of the fork of the forked arm to aid in or facilitate
the maintenance of the horizontality of the scale pan. I also avoid the
expense of connecting the stopping projection of the steelyard to the steel-
yard bar or its prongs by a fork or curved bar of connection.
Consequently what I claim is my improved manufacture of letter scale as
made, not only with its pendulous weight K connected with the scale pan F
by a forked arm H, H, I, provided with bearings h, i, for receiving and
resting on knife edges of a bar I extended from the steelyard, as specified, but
with a bar steelyard E made without any fork, and extended into a stationary
staple or stop g, the whole being arranged in manner and to operate as
specified.
Witnesses,
ARTHUR NEILL.
F. P. HALE, J³.
THADDEUS FAIRBANKS. (L.S.)