IMPROVEMENTS IN BALANCES
Year: 1882

page_text: LETTERS PATENT to Herbert John Haddan, of Kensington, Middlesex for an
invention of IMPROVEMENTS IN BALANCES A communication from abroad
by Frederick Anton Roeder of Cincinnati United States
COMPLETE SPECIFICATION filed by the said Herbert John Haddan at the
Office of the Commissioners of Patents on the 16th August 1882.
HERBERT JOHN HADDAN, of Kensington, Middlesex IMPROVEMENTS IN BALANCES
a communication from abroad by Frederick Anton Roeder of Cincinnati United
States
In the drawing accompanying and illustrating this specification, Fig. 1 is a
perspective view, in elevation, of a simple form of scale suitable for chemists use.
Fig. 2 is a similar perspective view of a "Counter scale" suitable for apothecaries,
or grocers use, in which the boxing, is omitted in order to better exhibit the
construction of the working parts. Fig. 3 is a vertical cross section of a platform
scale showing the relative arrangement of the levers and pivotal bearings, and
Fig. 4 is a detached vertical section of an arresting device used on the platform
scales but applicable to others as well.
Referring to the drawings, on which the letters of reference correspond with
those used in this specification A (Fig. 1) designates a scale beam centrally pivoted
upon a horizontal wire a constituting one of the long sides of a rectangular
frame B-The remaining sides b₁ be be of the frame B and also the diagonal cross
braces c¹ care metal rods or tubes soldered or otherwise rigidly secured together,
the wire a being similarly secured and held in tension between the short sides
against the resistance of the braces c² c²-The frame B may be mounted upon a
column C, rising from a base piece D, upon which it is secured by screws passing
through a suitable foot or in any other convenient manner.
The beam A is strengthened by guy rods d d extending diagonally above the
same from its ends to a central standard e, also utilized as a pointer in connection
with an arc shaped dial piece ƒ secured above the base or upon standards rising
from either side of the frame B.

page_text: The standarde is provided with a screw thread, and thumb screw 8, which
as a movable weight to adjust the centre of gravity of the scale
serves
beam.
I also extend the standard below the scale beam and provide a similar movable
weight 8 on such extension for a similar purpose-A third weight & projecting
laterally may also be pivoted upon the standard e whose projecting end being
adjusted to one side or the other of the perpendicular plane of suspensiou, changes
the centre of gravity laterally. By means of these adjustments the operations of
the scale may be very accurately regulated.
The scale pans D D are hung below the beam A by the usual pendant yokes
upon torsional wire frames B₁ each substantially similar in construction to the
frame B heretofore described, excepting that the peripheral wire is in the frame B¹,
continued entirely around the skeleton formed by the diagonal braces so as to
furnish two wire sides a² as for torsional pivots-Each frame B¹ is secured to the
beam A at the centre of one of its long sides a², and to the corresponding centre of
its other long side a³, the pendant holding the scale pan is secured, thus forming
a suspended link having two pivot connections both formed of wire acting
torsionally.
By means of this system of central and torsional pivots the utmost delicacy and
accuracy in the operation of the scale beam is attained.
The frames B are constructed of very light tubing, preferably of metal, though
I have found other material (such as glass) practicable to a certain degree.
For the purpose of arresting the vibratory movement of the beam and pendants
and relieving the frames B₁ of the weight of the scale pans when not in use, I
employ the following devices.
Elastic strips or springs E E are secured at one side of the base plate, their free
Beneath and
ends extending to and beneath the pans D, normally out of contact.
at right angles with the strips E E is journalled a shaft F, having thereon cams
or eccentrics g-The parts are so arranged that by rotation of the shaft F, the
eccentrics lift the strips E E against the bottoms of the scale pans and prevent
motion.
The elasticity of the strips carries them back to their normal position when the
cams are rotated out of contact, and the free movement of the beam and pendants
is again permitted-The construction of the balance shown in Figure 2 does not
materially differ from that described, excepting in the introduction of an auxiliary
parallel scale beam A beneath and in the vertical plane of the first.
In this case the central pivot frame B is furnished with two long sides of
The ends of
stretched wire each forming the pivot for one of the scale beams.
the beams A A' are secured in a similar manner to the upper and lower sides
of the frames B' B¹ which frames are thus suspended between the scale beams.
The central supporting frame is supported in a vertical plane above the base
by extending the vertical sides of the frame into standards secured to the base
plate
The scale pans D, are in this instance held above the ends of the scale beams.
upon suitable standards rising from the cross braces of the frame B¹ B-The
pivotal arrangement of the two scale beams is such that the scale pans are always
maintained in a perpendicular plane since the frames B¹ B¹ maintain their parallelism
at all times.
The other parts of the balance are constructed and arranged as before described-
It will be readily seen that the aggregate weights of the movable parts and the
weights placed in the scale pans are distributed over the six wires constituting
supporting pivots, whereby great strength and durability is attained without
resort to large wires or rods, and the sensitiveness and accuracy of the balance is
preserved.
The application of the essential principles of this invention to platform scales is
shown in Fig. 3.
The platform P, rests by means of bifurcated standards h, upon the lower wire

page_text: sides of fame such as has been before described and are designated in the other
figures by the same letter of reference.
These frames are suspended from two bifurcated levers L' L' of the second class,
connection being rigidly made with the upper wire sides of the frames to the levers
which are in turn pivotally supported at their bifurcated ends, respectively, upon
wire pivots forming the upper sides of frames B, mounted upon the base plate M.
The levers L' L' are arranged to vibrate in the same plane, one above the other,
and are connected by a frame B³, of the general construction before described, the
frame B³, serving as a link suspended between the two levers uniting the free end
of the smaller lever L2, with an approximately central point of the long lever L'—
The outer or free end of the lever L³, is connected by a similar pivot wire frame B
with the end of the balance lever L³.
The pendant scale pan N, may be suspended by a similar pivot wire frame B³
and the balance lever L³, itself be supported pivotally by a similar frame B6,
suitably elevated from the base M.
The application of the torsional principle thus throughout conduces to a more
accurate and sensitive action of the apparatus, but it may be confined to the main
supporting levers if desired. I find it desirable to provide a friction brake to
operate upon the balance lever L³, and modify to some extent its sensitive
vibrating action in order to expedite its use. A bar spring i secured to any
fixed portion of the apparatus and resting with some force against the lever L³, is
all that is required.
It remains but to describe the arresting device which while embodying the same
principles as that before described is slightly different in construction. In this
case I employ two parallel shafts K K', journaled in the base plate, carrying two
sets of corresponding crank arms ppl to whose wrists are pivoted "parallel rods"
or plates m, arranged to rise beneath the standards h, and support the same when
the shafts are rotated. The rotation of one of the shafts is effected by a hand
levern, secured upon its projecting end, operating in connection with a suitable
rack bar, and this movement is communicated to the second shaft through the
parallel rod or plate m, and cranks p p¹, strips of metal E, are employed to prevent
frictional displacement, which has substantially the function of the spring E.
CLAIMS
First. A scale beam, having its fulcrum support and terminal pendant con-
nections formed of stretched metallic wires acting torsionally as set forth.
Second. The frame B, constructed substantially of diagonal cross braces, and a
wire stretched between and around the ends of the braces and constituting one or
more of the peripheral sides of a rectangular frame, said side or sides being utilized
as a torsional pivot for a scale beam substantially as set forth.
Third. In combination with the scale beam A, the frames B, having diagonal
braces holding wire in tension used as the terminal supports for the scale pendants
substantially as set forth.
Fourth. In a torsional pivot balance, one or more auxiliary scale beams pivoted
in the same vertical plane with the main beam and connected therewith through
the terminal pivot frames substantially as and for the purpose specified.
Fifth. In a torsional pivot balance the combination of the main and auxiliary
beams A A', and central and terminal pivot frames B B¹, substantially as set
forth.
Sixth. In a torsional pivot balance the frames B B¹ as constructed, each con-
consisting of a wire stretched around the extremities of two cross bars diagonally
arranged, substantially as set forth.
Seventh. The shaft F provided with eccentric cams g in combination with the
springs E as a motion arrester for balances, arranged and operating substantially
as set forth.
Eighth. In a platform scale the bifurcated levers L' L supported upon stretched

page_text: wire pivots and connected by a suspended link B³ secured to the levers upon
stretched wire pivots all acting torsionally substantially as set forth.
Ninth. In a platform scale in combination with the system of levers L¹ L², and
their connections the torsion frames B¹ B', suspended from the levers, and con-
stituting the pivoted supports of the platform P, substantially as set forth.
Tenth. In a platform scale in combination with the supporting lever system the
"torsion frame" B* connecting the supporting levers with the balance beam,
substantially as set forth.
Eleventh. In a platform scale in combination with the standards h, supporting
the platform upon the compound levers, the motion arresters consisting of the
pivots or shafts having thereon cranks p, operating parallel plates m, and hand
lever n, substantially as specified.
In Witness whereof I the said Herbert John Haddan have hereunto set my
hand and seal this twenty-fifth day of May A.D. 1882.