Year: 1886

page_text: I, REGINALD HADDAN, of the firm of Herbert & Co, Patent Agents, of 67 Strand,
in the County of Middlesex, Civil Engineer, do hereby declare the nature of my said
invention,, a communication to me from abroad by The Torsion Balance and Scale
Company, of Cincinnati, United States of America, and in what manner the same
is to be performed to be particularly described and ascertained in and by the
following statement :-
This invention relates to weighing balances, having more particular reference to
that class of such balances in which stretched wires, bands, or strips of elastic
material such as metal are employed for use as pivots or pivotal bearings for the
beam or its connections; and it consists in the several features of improvement
hereinafter more fully described, applicable to the various forms in which balances
are commonly used, tending to render such balances practicable and efficient for all
the uses and purposes to which they may be applied.
In general, these features embody, (1) the employment of wires or bands of
angular cross-section as contra distinguished from cylindrical wires or strips,
whereby the strips may be more firmly secured and maintained in their holdings
against torsional displacement; (2) in the application of the elastic pivot directly
to the beam as part of the beam-structure, in such manner as to maintain the
pivots in the proper tension; (3) in the combination, with the beam, of a counter-
poise properly proportioned and arranged to neutralize by its gravitating action the
molecular resistance of the pivot or pivots to the beam oscillation; and, further, to
the combination with such beam and poise of an auxiliary beam and poise pro-
portioned and arranged to compensate any abnormal action of the primary poise
due to improper alignment of the base support of the; balance; (4) to the construc-
tion of the balance embodying a pivoted balance-beam combined with an auxiliary
beam or "radius-arm and a rigid platform support connecting their terminal
pivots.
The several features of the invention are illustrated in the drawings herewith, in
which drawings-
Fig. 1 is a side elevation of a double beam scale complete, of a preferred style of
construction for ordinary counter use; Fig. 2 an end elevation of the same; Fig. 3
a sectional elevation of the same, exhibiting the central supporting frame; Fig. 4 a
detail end view of the beam showing the construction by which the pivot-band is
clamped thereto; Fig. 5 is a detail view of a modified construction of a pivot or
*" torsion" frame of cheaper construction adapted to be used with the scale illustrated
in the previous figures; Fig. 6 a side elevation of a balance of the "steelyard."

page_text: variety, illustrating the same and other features of the invention; Figs. 7, 8 and 9
details of parts of the same exhibiting the mode of construction more fully; Fig. 10
a side elevation of a steelyard balance exhibiting, in connection with the foregoing
features of invention, the auxiliary beam or "pointer" and the auxiliary compen-
sating poise; Fig. 11 a plan view of the beam showing details of construction.
Referring now to the drawings, in aid of the following description in which the
parts are designated by reference lotters: A, B, designate the primary and auxiliary
beams, respectively, of a common form of balance, mounted centrally on torsion
pivots in a common vertical plane and connected terminally by movable frames
carrying torsion pivots, all as hereinafter more fully described.
The balance shown, is constructed, preferably, of metal: the beams, base, frames,
and pan-supports, being cast or "drop-forged;" and the pivots being elastic bands,
preferably of steel.
The central support and the terminal connecting frames, C, C, C², respectively,
of the beams, are flat webs constituting in effect, a frame of diagonal struts, as
shown, about whose periphery, in a suitable groove, a steel or other elastic endless
band or strip, p, is secured in tension, describing an approximately rectangular
figure. Those portions of the band, p, constituting the upper and lower sides of
the figure are free between the ends of the frame constituting the holding abut-
ments, and are utilized as the pivotal bearings of the beams. The central and end
frames, C, C, do not differ essentially in form, excepting that the central frame, C,
is provided with cleats, c, adapting it to rest upon and be secured to a base, D, upon
suitable pedestals d, d; and the end. frames O', C', have an upward extension, c¹,
of the web, to which a "spider" s, is secured for the support of the scale pan, s¹,
and a similar lower extension c², serving as a stop to limit the oscillating movement
of the beams.
In all of the frames, shown in the complete balance, (Figs. 1, 2, 3) one entire
end, c, of each frame is made separable at a vertical line of division; and, by the
insertion of wedges, c, between the parts at the line of separation, the separable
part is forced outward, thus tensioning the pivots p.
In the construction of frame C, shown in Fig. 5, however, to secure the proper
tensioning of the bands, the frame is expanded by compression (hammering) at the
central part where the diagonal braces in effect cross each other. To this end, said
frame may be made of wrought iron or steel by "drop forging" or otherwise as
may be most convenient for the purpose. The uniform tension of the bands may
be ascertained and secured in all cases by reference to the pitch of the musical note
produced by their vibration between their holding points.
The
The construction by which the pivots are secured to the beams is indicated in
Fig. 4. The beam is recessed crosswise the width of the pivot-band, and the pivot
secured in such recess by a suitably formed cleat, a, attached by screws.
bottom of the recess and the corresponding face of the holding cleat form an
opening corresponding with the cross section of the pivot-as, rectangular,
triangular and such like, and constitutes a clamp, preventing torsional displacements
of the pivots at such points; the object being to secure a rigid and durable holding
without resort to solder; to which end it is essential that the pivot cross-section
possess at least one plane side.
The base of the balance is provided with one fixed foot, e, and two adjustable
screw supports, e¹, e¹, so that, by the adjustment of the latter, the balance may be
properly adjusted in a horizontal plane.
It remains to describe the counterpoise W, which is a weight mounted upon a
standard, w, rising vertically above the fulcrum pivot of the beams, A, B. The
standard is, by suitable extensions, w³, supported upon the lower beam; thus
giving an extended are of movement to the weight W in the oscillations of the
beam; and the weight has a limited vertical adjustment by screw-threads upon its
standard. The weight, W, being properly proportioned, exercises a most important
function in counteracting the combined torsional resistance of the pivots; and, by
means of its vertical adjustment, may be rendered more or less effective—that is,

page_text: to more or less completely neutralize the torsional resistance of the pivots-as
desired, and the sensitiveness of the balance thus regulated.
'
The construction thus described embodies and illustrates the following features
of the invention, (1) The use of angular sectioned bands or pivots which admit of
holding devices securing the pivots against torsional displacement by the form and
"fit" of the holding surfaces against the plane surface or surfaces of the pivot,
without solder or other extraneous means such as are required with cylindrical
pivots. This is important, inasmuch as soldering or brazing is liable to impair the
temper" of the pivot and destroy its elasticity, and moreover, the holding of
solder or a clamp upon a cylindrical surface is comparatively insecure against
torsional displacement. (2) The counterpoise, for neutralizing the torsional
resistance of the pivots, by which, in the oscillations of the beam, the gravity of
the counterpoise is thrown to the descending end of the beam in degree pro-
portioned to the degree of oscillation and to the total amount of torsional
resistance developed by said oscillation. (3) The "radius-arm" (which in this case
is utilized as a duplicate scale beam), and the rigid pan support connecting the
'terminal pivots of the two beams the construction being such as to preserve
the parallelism and true perpendicularity of the scale pan supports. (4) The
arrangement of flat pivots or bands in a horizontal plane.
Figs. 6, 7, 8 and 9 exhibit details of a "steelyard" balance embodying many of
these features of invention. The general form and functions of this style of
balance being well known requires no special description.
The invention is applied by attaching to the beam A¹, near one end a horizontal
open yoke, b, beneath the beam and across its linear axis. Within this yoke the
fulcrum and scale pan pivots p¹, p³, are secured, upon vertical posts f, passing
through and held in plates g, g, arranged horizontally upon and near the ends of
the yoke above and below. The plates themselves are held apart, horizontally by
vertical wedges h, inserted against inner projections of the yoke as shown, while
the posts f, have a vertical adjustment, by means of nuts threaded upon their
upper and lower projecting ends. By driving the wedges h, the plates g, are forced
borizontally apart, thus tensioning the pivots p', p², and by the vertical adjustment
of the posts f, the pivots are brought into different horizontal planes as will be
readily understood. The object of the latter adjustment is to bring the scale-pan-
pivot into a lower horizontal plane than the fulcrum-pivot, with a view to secure
the proper sensitive action of the balance under load; for, it is found by experience
that if the pivots are, under these conditions, in the same horizontal plane, and the
balance adjusted, the addition of load upon the scale pan destroys or impairs the
regularity of action, whereas, by lowering the relative position of the terminal
pivot the sensitiveness remains unimpaired in loading the balance.
The fulcrum pivot is secured, and the beam supported, by means of a cleat or
projection i, upon the base frame or pedestal E, clamping the pivot p¹, and the scale
pan is suspended by means of a cleat j, from the pivot p³, both these cleats
clamping the pivots, centrally between their holding posts f, by a construction
similar to that exbibited in Fig. 4.
The construction showu in Figs. 6, 7, 8 and exhibits and embodies (1) the
attachment of the pivot directly to the beam as part of its structure-in this case
by tensioning approximately in the plane of the major axis of an open yoke
forming part of the beam structure; (2) The arrangement of the flat pivots in a
vertical plane-which is advantageous in balances of the steelyard variety or
others where the entire weight of the balance beam and load is carried upon a
single fulcrum, in that it prevents "sagging" of the pivot to a greater extent;
(3) The arrangement of the fulcrum relative to the beam, whereby the centre of
gravity is maintained above the fulcrum and the effect of the compensating poise
obtained by the weight of the beam itself.
Figs. 10 and 11, exhibit the construction of a balance of the steelyard variety
embodying additional features of the invention, besides some of those already
referred to employed in a slightly different manner. In this balance A² designates

page_text: the principal beain (a leyer of the first class); B², its supporting standard; C², the
base plate; B³, an auxiliary supporting standard; D2, an auxiliary beam (a lever
of the second class) utilized as a pointer or indicating finger. The beam A²,
terminates at its forward end in diagonally crossed braces or prongs b³, (Fig. 11),
around the ends of which is stretched the elastic band or strip. p³, suitably
tensioned. The arrangement of the prongs b², as struts in relation to the band p³,
as will be observed, produces a strong resisting frame, which, with the minimum of
weight and strength of material in the beam, allows the tensioning of the pivot to
any degree desired; since its strains in one direction are neutralized by corre-
sponding strains in the opposite direction. One of the free sides of the pivot p³,
is secured to the standard B2, as the fulcrum-pivot of the balance, and to the other
is secured the scale pan support.
At a convenient distance below the fulcrum pivot upon the standard B³, a
" torsion-frame" 63, is arranged, corresponding in size and construction with that
formed by the crossed struts, 6, of the main beam. One of the free sides of its
pivot is attached to the standard B and the other to the rigid scale-pan support E²,
which, being rigidly connected also with the band p³, of the beam, A', is extended
upward (or downward as preferred) and supports the scale pan or weight
platform S. It will be observed that the "torsion frame" 63, acts, in this case,
solely as a "radius-arm" to preserve the perpendicularity of the scale-pan support
and not as an auxiliary beam to share the load upon the balance.
The counterpoise-weight, W2, is applied by means of a rigid vertical standard
rising above the fulcrum pivot of the beam and acts as before described.
In the application of the compensating poise herein before described, it is
absolutely essential to accurate weighing, that the poise should be maintained in a
true vertical position when the beam is normally at rost and "balanced," in which
position the poise is neutral and inert. To secure this it is also necessary to adjust
the balance in perfect vertical and horizontal alignment, which, obviously is often
difficult to accomplish and almost impossible to maintain. To overcome this
difficulty, an auxiliary lever D2, (of the second class) fulcrumed upon an independent
support B³, and provided with a counterpoise w², is connected with the main beam
at its remote end by a vertical link e. Torsional pivots may be employed for all
these additional connections and bearings. This secondary lever may be utilized
as a pointer moving over a graduated arc, and also as a secondary weight-beam
with sliding weight to indicate fractions of the unit of weight measure.
Now it will be apparent that when the parts are properly adjusted and the scale
structure is in proper alignment, the two poises W2, w², are in their neutral vertical
positions, and a deflection of the main beam and corresponding deflection of the
auxiliary beam brings into action the statical moments of both poises in unison
against the torsional resistance of the pivots, producing the beneficial function
above set forth. But, should the alignment of the scale structure be imperfect,
whereby the statical moment of one of the poises is brought into action abnormally
in one direction relative to the beam and pivots, the statical moment of the other
poise is similarly brought into action in the opposite direction and with the
opposite effect upon the beam and pivots; and, these poises being properly pro-
portioned and adjusted, the resulting effect is a neutral condition corresponding
with a perfect alignment. If now under such circumstances the balance be put to
use, the deflection of the beam brings the poises into normal action with the
beneficial results first described. It will be evident therefore that the structure thus
described is to a great extent independent of such accuracy of alignment as would
otherwise be required, and its indicated results of weighing will be correspondingly
more accurate. It will be understood that the construction shown is by way of
illustration merely; and that this feature of the invention may be embodied in
other mechanical forms of torsion balances producing a similar result.
The Figures last described, illustrate (1) the combination with a beam and
compensating poise, of an auxiliary beam or lever and compensating poise, acting in
the manner and for the purpose described; (2) the construction of a scale beam

page_text: with projections arranged as struts around which an elastic band or strip is
tensioned in such manner as to counteract its own strains.
The figures and description herein contained, are intended to illustrate the
embodiment of the described principles of construction in practicable and useful
structures, but the invention is not confined to these precise forms of balances, but
may be used in platform scales for weighing heavy bodies, or in machinery for
testing metals and such like, wherever a balance beam is employed.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what
I claim is:
1. In "torsion" balances a pivot or pivots consisting of a strip, band, or wire of
elastic material such as metal, having a cross section embodying one or more plane
sides, in combination with holding abutments in which the pivot is held between
correspondingly formed clamping surfaces against torsional displacement.
2. In torsion balances an expansible frame for holding the pivot wire or band
and constituting a connection or support for the bean or beams, whereby the band
may be suitably tensioned by the expansion of the frame.
3. In a torsional-pivot balance a counterpoise weight carried by the beam above
the fulcrum pivot, proportioned to the torsional resistance of the pivot or pivots and
arranged so that its statical moment when carried by the oscillations of the beam
out of the perpendicular tends to counteract said torsional resistance.
4. Arranging the counterpoise weight adjustably upon a vertical standard to
vary its effective gravity by varying its limits of lateral movement.
5. Combining with the main balance beam and counterpoise weight of a torsional
balance, an auxiliary beam or lever independently fulcrumed and carrying a
similarly acting counterpoise weight all so arranged that an abnormal action of the
primary counterpoise due to defective alignment of the balance and affecting the
balanco beam in one direction, (i.e. on one side of its fulcrum) will be counter-
balanced by a similar abnormal action of the auxiliary counterpoise affecting the
balance beam in the other direction (i.e. at the opposite side of its fulcrum).
6. In combination with the balance beam of a torsional balance, a lever pivoted
in the vertical plane of the beam fulcrum and extending parallel with the beam,
and carrying a terminal pivot in the vertical plane of the terminal beam-pivot;
and a vertical platform-support rigidly connecting the terminal pivots of the
beam and the auxiliary lever, whereby the latter acts as a "radius-arm to
preserve the perpendicularity of the scale pan or platform support.
"
7. The attachment of one or more elastic pivots directly to the beam as part of
its structure and the construction of the beam in such manner as to maintain the
tension of the pivots by projections or struts in the plane of tension.
8. The combination of flat bands or pivots with the beam, the former being
arranged in a vertical plane.
9. The combination of the pivots with the beam in such relative horizontal
plane as that the centre of mass of the beam is located above the fulcrum, thereby
acting as a counterpoise to pivotal resistance.
10. The combination of torsion pivots with a steelyard beam in such manner
that the pivots may be adjusted relatively in a vertical plane.