Improvements in Balance Scales.
Year: 1891

page_text: Date of Application, 22nd Sept., 1891-Accepted, 24th Oct., 1891
COMPLETE SPECIFICATION.
Improvements in Balance Scales.
We RICHARD MELANCTHON SHAFFER, Machinist, of 232 North Entaw
Street and ADOLPH THOMAS PFAFF, Grocer, of 440 North Gay Street, both in
Baltimore, State of Maryland, United States of America do hereby declare the
nature of this invention and in what manner the same is to be performed, to be
particularly described and ascertained in and by the following statement :-
The object of our invention is to dispense with the use of the detached weights
which ordinarily accompany the usual forms of balance or counter scales. These
graduated weights being more or less numerous are continually being misplaced or
fost, and are liable to roll off the counter or be scattered promiscuously thereon,
or be stolen on account of their detached character. Our invention seeks to
preserve all the positive advantages of this class of scales by weighing with weights
instead of springs, and yet present such a construction of scales as shall be free
from the objection of detached weights and at the same time be simple compact,
accurate, and efficient. It consists mainly in placing one of the pans of the balance
at a lower level than the other, and providing a series of weights connected with a
series of pulls or adjusting handles, one or any number of which weights may be
placed in the pan to weigh any body placed in the other pan, the pulls or handles
being each plainly marked with the weight which they represent as hereinafter
fully described.
Reference is to be had to the accompanying drawings, forming part of this
Specification wherein,
Figure 1 is a perspective view of the exterior of the scales;
Figure 2 is a vertical longitudinal section;
Figure 3 is a vertical transverse section through line x-x; and
Figure 4 are details of modified combinations.
In the drawing, A. represents the outer case of the scales, which case is
preferably in the form of a rectangular box, but may be made of any other shape.
It is formed of cast iron, wood, marble or any other desirable material. B is the
lever frame which is fulcrumed at a upon knife edges sustained upon suitable
supports fixed to the inner sides of the cuse. At opposite ends of this lever frame
are the stirrup-shaped supports C and C¹, which are supported upon the ends of
the lever frame by means of knife edges b. From one of these supports C there
rises a rod D extending through the top of the case and supporting the pan E or in
the place of it the slab, disc, or scoop upon or in which the articles to be weighed
are placed. At the other end of the lever frame the support C¹ is connected within
the case to a pan or table F upon which the weights are to be placed. These
weights are shown at G, and they vary in their gravity to correspond with the
subdivisions ordinarily used or any that may be desired, as for instance + oz., oz.,
1 oz., 2 oz., lb., lb., 1 lb., 2 lbs. They are arranged in one, two or more
rows immediately above the weight support F and out of contact with the same.
As shown there are two rows of them, and as their connections for depositing them
upon the weight support F and lifting them off again are all the same, it will be
sufficient to describe one of them. Each weight has a loose link c that connects it
to an arm d, pivoted or hung at one end upon a shaft H and resting at its other
end upon a came loosely hung on a shaft H¹ parallel to H. This cam has an
extension, that is connected by links g to a vertical slide rod I that extends
through the top of the case and terminates in a knob or disk / marked with a
figure or figures to correspond with the weight connected thereto. There is one of
these slide rods and its connections for each weight and the rods are guided in
their vertical movement by cross bars J J. K are springs which may be of any

page_text: shape and cross section and which as shown are of flat spring steel curved and
resting upon the top of the lift arms-d and connected to the cross bar L above.
The action of these devices is as follows:
When it is desired to weigh any specified amount of material, the knob or pull/
indicating that amount is pulled up, or several of them aggregating that amount are
pulled up, and the material placed on the pan or scoop E will be when a balance is
obtained, exactly the desired amount. 'The effect of raising one of the pulls is to
throw the came down and drop the arm d to a position in which the weight of that
arm is deposited upon and supported by the lower pan or table, accomplishing in
effect the same result that is reached when the tradesman places a weight of definite
size upon the table of the counter scales or balance. After the article has been
weighed, the pull rod is forced down, whereby the cam e is partially rotated, so as
to lift the armid and raise, through the link c, the weight until it is off the table or
pan which supported it. The cam enables this movement to be easily and smoothly
effected with very little effort on the part of the operator. The function of the
spring K is to hold each arm steadily to place and prevent rattling and looseness.
M is a sliding cover which has dovetail edges that slide beneath the two cross
bars J, J. Nis a longitudinal screw rod arranged in the lever frame and provided
with a weightin, turning. on it like a nut, and serving as an adjusting weight by
which the equilibrium of the balance is preserved or readjusted when necessary.
0,0¹tare stays or radially swinging arms for preserving the parallel movement of
the pans and the vertical positions of their rods. These stays are jointed at one
end inside the case to a stationary part of the same, immediately above the fulcrum
of the mainframe and one of said stays is jointed at its opposite end to the rod
which supports the upper pan, and the other stay is similarly jointed to the top of
a rod 0, which rises from the lower pan.
In carrying out tour. invention we do not confine ourselves to the special con-
struction and arrangement of parts shown as these may be changed without
departing from our invention. Thus. for. instance the vertical slide rods..I with
links, arms, and cams e nay be replaced by any other operating mechanism..for
raising and lowering the weights, such as tilting crank handle levers, or cord and
pulleys, as shown in Figure 4. The springs K may also be entirely dispensed with
if desired.
We are aware that it is not new to provide a scale beam with a series of' weights
of the same gravity spaced along the beam for different leverages on the same, and
arranged to be placed upon or removed from the beam by adjusting.devices, and
we make no claim to such arrangement. Our invention is distinctive in the different
gravities of the weights, and the fact that they are all placed upon a support, having
a single point of connection with the fulcrumed frame and a constant leverage.
Having now particularly described and ascertained the nature of our said inven-
tion, and in what manner the same is to be performed, we 'declare' that what we
.claim is-
1. A pair of balance scales; consisting of a fulcrumed frame bearing.at.one:end
apan or its described equivalent, and at the other end a support for adjustable
weights, having a single point of connection with the fulcrumed frame, a series of
weights of different gravities, and adjusting devices for each for placing them singly
or collectively upon said support ito balance the articles in the weighing pan,
substantially as described.
78
22. A pair of balance scales, consisting of a fulcrumed frame bearing at one end
a pan or its described equivalent, and at the other end a weight support placed at
ta lower level and having a single point of connection with the fulcrumed frame, a
series of weights of different gravities sustained just above the weight support,
adjusting devices for depositing said weights upon the support, an outer case
enclosing the weights and weight support, and operating knobs.or handles arranged
outside the casing marked to correspond with the weights which they represent and
'connected to their-adjusting mechanism, substantially as shown and.described.

page_text: 3. The combination with an enclosing case, of a fulcrumed main frame having at
one end a rod extending up through the case and bearing a pan or its described
equivalent, and having at the other end a weight support within the case for
adjustable weights with vertical standard O' rising above the weight support, and
the swinging or oscillating stay arms 0 O' pivoted or hung centrally above the
fulcrum of the main frame and pivoted the one to the rod of the pan below the
same, and the other to the standard of the weight support above the latter, substan-
tially as shown and described.
4. The combination with the weight support in a balance scales; of a series of
weights loosely hung above it, the link c loosely connected thereto, the lifting
cams e, arranged beneath the arms and provided with extensions f, the vertical pull
rods and the link connecting the same to the cam extensions, substantially as
shown and described.
5. The combination with the weight support, the weights and the weight adjusting
devices; of a series of springs for tightly holding the adjusting devices to place
against looseness, substantially as shown and described.
6. The combination with the outer case having balance frame, weight support,
weights, and adjusting devices within; of the cross bar L, springs K, attached to
the cross bar and pressing upon the weight adjusting arms, the under cut guide
bars J, and the dovetail sliding cover M, substantially as shown and described.
7. A balance scales, consisting of an enclosing case, an external weighing pan or
its described equivalent, a series of external pulls or handles marked with the
specific weights which they represent, and a series of weights of different gravities,
a pan or support having a single point of connection with the fulcrum frame, and
adjusting devices within the case and connected to said pulls or handles, substan-
tially as described to cause the weights to be brought at will into or out of
weighing action, as set forth.
Dated this 22nd day of September 1891.
R. M. SHAFFER.
A. T. PFAFF.
By A. M. & Wm. Clark,
53, Chancery Lane, Loudon, Chartered Patent Agents.