IMPROVEMENTS IN LETTER BALANCES AND OTHER WEIGHING APPARATUS
Year: 1864

page_text: PROVISIONAL SPECIFICATION left by Edward Butes at the Office of
the Commissioners of Patents, with his Petition, on the 15th July
1864.
I, EDWARD BUTES, of Cross Street, Wilderness Row, in the County of
Middlesex, Fancy Goods Manufacturer, do hereby declare the nature of the
said Invention for "IMPROVEMENTS IN LETTER BALANCES AND OTHER WEIGHING
APPARATUS," to be as follows:-
(
My improvements in letter balances and weighing machines relate to the
application of a constant weight to a bent lever, whereby different weights
attached to the opposite end of such lever are determined and ascertained by
the moving of the constant weight from a vertical and pendant position on its
fulcrum to a position more or less towards the horizontal, and where it will
possess greater or less leverage over the opposite end to which the body to be
weighed is suspended, and my Invention consists of a particular application
and combination of the parts, whereby the different weights are determined
and indicated. For this purpose I use a bent lever mounted on a fulcrum
pin suspended by a metal strap or fork, which for letter balances I make con-
venient to hold by the finger and thumb, but which may be supported by a
suitable stand like an ordinary beam weighing apparatus. When the apparatus
is at rest the weight hangs immediately under the fulcrum, while the upper
end of the lever is upwards from that point and inclined a little to the right
or to the left of the vertical line. This end of the lever is furnished with a
scule, pan, or means of attaching the article to be weighed; for letters a

page_text: clip or forked wire is convenient, anything attached to this end of the lever
causes it to preponderate and fall a little, whereby the pendant weight is
deflected a little out of its vertical pendant position, and until an equilibrium
is established. On the middle of this lever and around its fulcrum I fix or
support a dial, and on the fulcrum pin I place a double index hand, which
remains in a horizontal position and points to opposite points of the dial's cir-
cumference, it retains this horizontal position by reason of a pendant weight
formed of a piece with or fixed to the double hand, thus the hand hangs freely
on the fulcrum pin, it is free to retain its normal position. For letter balances
the dial is graduated at one part of its circumference with ounces and fractions
of ounces to which the one hand points, while the opposite hand points to a
scale graduated and marked with the charges for postage according to the
weight; different rates of postage, that is to say, for English and foreign
letters may be indicated on the same scale and by same index hand. The
scale may be graduated for troy, avoirdupois, or other weights, and may even
exist on the same dial, and other numbers of hands may be adopted; but in
each case I make them in one piece or fix them together, and they maintain
their position by the gravitation of a preponderating body, as before described.
For heavy goods I adopt the same arrangement, but of course making the
parts strong in proportion, and with a stand or means of suspending the lever
on its fulcrum.