IMPROVEMENTS IN SCALES
Year: 1885

page_text: I, HERBERT JOHN HADDAN, of 67, Strand, in the City of Westminster, Civil
Engineer, do hereby declare the nature of my invention for IMPROVEMENTS IN
SCALES, a communication to me from abroad by Richard Watson, of New York
City, United States, Manufacturer, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement:-
In the weighing scales heretofore in use, certain inaccuracies were produced in
weighing when the weight was not placed directly at the centre of the scale pan,
but accidentally shifted to or placed at one or the other side of the vertical-centre-
line of the same.
This invention relates to an improved compensating attachment for weighing
scales, by which the accurate weight of the article placed on the scale-pan may be
obtained, whatever may be its position relative to the centre of the scale-pan; and
the invention consists of a scale-beam and scale-pan, supported by knife-edges at
the end of the same, the shank of the scale-pan having a slotted plate which is
connected by an oscillating link with a fixed slotted plate of the supporting stand
of the scale.
The link rests on bevelled edges of the slotted plates and bears against the same.
It is retained on the plates by means of lugs pivoted to the same.
In the accompanying drawings Fig 1 is a side-elevation, Fig 2 is a detail side-
view of the compensating attachment, partly in vertical section on line xx, Fig 4,
Fig 3 is an end-view, and Fig 4 a horizontal section of the same line y y, Fig 2.
A is the supporting stand, and B the scale-beam of the same, which carries on
knife-edges at the outer end, the shank C of a scale-pan B¹. The shank C of the
scale-pan B¹ is provided at its lower end with an adjustable plate C¹ that is
attached by a slot b and clamp-screw 6¹ to the shank C. The lower part of the
plate C has an opening a, the lower edge of which is bevelled. On the bevelled
edge of the opening a, rests a slotted connecting link D, that extends from the
plate C¹ to a fixed vertical plate C³ that is applied to the supporting frame A of the
weighing scale. The fixed plate C2 is also provided with an opening a¹, having a
bevelled lower edge, on which rests the opposite end of the connecting link D. The
CDi 1

page_text: plate C is vertically adjustable on the frame A, like the plate C¹ on the shank C,
by means of a slot and clamping screw, as shown in Figa 2 and 3. The connecting
link D is held in position on the plates C¹ C² and prevented from shifting in any
direction by means of lugs d d', which are applied to both plates C₁ C. The lugs d
extend in upward direction through slots d of the link D and bear against the
bevelled edges of the slots d as shown in Fig 2. The lugs d' are pivoted to the
plates C C above the link D, and prevent the disengaging of the link D from the
steps dd, by means of the bevelled edges of the openings of the supporting
plates C and C and of the slots d' of the connecting link D the friction of the
same with the plates C1 C2 during the oscillating of the scale-beam B and shank C
is reduced to a minimum. The vertical up and down motion of the shank C in
following the oscillations of the scale-beam B also oscillates the connecting link as
indicated in dotted lines in Fig 1. The link D holds the shank of the scale-pan in
vertical position and serves to compensate the effect of the weight on the scale-pan
whatever be its position thereon so as to indicate the correct weight of the article,
in an accurate and reliable manner.
The compensating attachment is enclosed by a casing or shell E, as shown in
section in Fig 1, so as to be protected against accidental injury.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is
1. The combination of a supporting frame, having a fixed end-plate, a scale-beam,
a scale-pan having a shank fulcrumed to said scale-beam, and an oscillating link
connecting the lower end of said shank with the fixed plate of the frame,
substantially as set forth.
2. The combination, of a supporting frame, having a slotted end-plate, a fulcrumed
scale-beam, a scale-pan, having a shank fulcrumed to the beam, a slotted plate,
attached to the lower end of the shank, an oscillating link connecting the slotted
plates of the shank and frame and means for retaining the link in connection with
said plates, substantially as set forth.
3. The combination, of a supporting frame, having a slotted end-plate, a scale-
beam, fulcrumed to the frame, a scale-pan having a shank fulcrumed to the scale-
beam, a slotted plate attached to the lower end of the shank, a slotted oscillating
link connecting the plates of the shank and frames, the contact edges of the plates
and link being bevelled; and retaining lugs attached to said plates, substantially as
set forth.