Improvements in Weighing Scales or Balances.
Year: 1888

page_text: Date of Application, 10th Aug., 1888
Complete Specification Left, 10th May, 1889-Accepted, 22nd June, 1889
PROVISIONAL SPECIFICATION.
Improvements in Weighing Scales or Balances.
I, CHARLES HENRY BARTLETT, of 2 and 3, Welsh Back, Bristol, in the County of
Gloucester, Weighing Machine Manufacturer, do hereby declare the nature of this
invention to be as follows:-
This Invention relates to weighing scales or balances, and particularly those in
which agate-stones are used as the bearing surfaces for the knife edge centres of
suspension or support of the beam and scale pans, and in this connection it has for
its object to prevent the liability to chip or otherwise injure the agate stones by
the jarring consequent on the violent deposit of the goods or of the weighing weights
on the pans of the scale.
To this end the invention consists in the interposition between one or both the
scale pans and the end centre bearings of a cushion or spring whereby the violence
of the shock is absorbed or transmitted with diminished force to the various centres
whether at the same or the opposite end of the beam. The cushion may be of india
rubber or a metal spring of suitable form may be used; the form and arrangement
depending on the particular kind of scales or balance to which the invention is
applied.
In a balance of the Roberval type, a cushion of india rubber may be placed
beneath a shoulder on the vertical pivot upon which the scale pan is carried; and in
a hanging scale it might be applied between the stirrup piece and the suspension
links of the scale pan.
The Invention also relates to the adjustment of a Roberval balance; and it consists
in the mode of applying an adjusting weight carried by a traversing screw intro:luced
at the middle of the beam of a counter balance of the Roberval type. The screw is
journalled in the beam in which it occupies preferably a diagonal position in a horizontal
plane so as to enable it to be readily turned from the side of the beam, the weight
being situated beneath and prevented from turning, by a plate forming part of the
beam whereby the weight is caused to traverse along the screw when the latter is
turned for the purpose of varying the position of the weight relatively to the axis of
suspension of the beam. The diagonal position of the screw enables a more minute
adjustment of the weight to be obtained, with a given pitch of thread.
Dated this 10th day of August. 1888.
C. H. BARTLETT,
By A. M. & Wm. Clark, Patent Agents, 53, Chancery Lane, London.
COMPLETE SPECIFICATION.
Improvements in Weighing-scales or Balances.
I, CHARLES HENRY BARTLETT, of 2 and 3 Welsh Back, Bristol, in the County of
Gloucester, Weighing Machine Manufacturer, 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 :-
This Invention relates to weighing-scales or balances generally and particularly
those in which agate stones are used as the bearing surfaces for the knife-edge centres
of suspension or support of the beam and scale-pans and in this connection it has for
its object to prevent the liability to chip or otherwise injure the agate stones or other
bearings and the wear or blunting of the knife edges by the jarring consequent on
the violent deposit of heavy weights on the pans of the scale.

page_text: To this end, the invention consists in the interposition between the scale-pans and
the end centre bearings of spring cushions whereby the violence of the shock is
absorbed or transmitted with diminished force to the various centres. The cushion
may be of india rubber or a metal spring of suitable form may be used, the form and
arrangement depending on the particular kind of scales or balance to which the
invention is applied.
The Invention also relates to the adjustment of a Roberval balance; and it consists
in the mode of applying an adjusting weight carried by a horizontal traversing screw
journaled in a diagonal position at the middle of the beam, the weight being caused
to traverse along the screw, for the purpose of varying its position relatively to the
axis of suspension, the diagonal position of the screw enabling a minute adjustment
of the weight to be obtained with a comparatively coarse thread.
Reference is to be had to the accompanying drawings forming part of this specifica-
tion, in which figure 1 is an end view partly in section and figure 2 a plan of part of
a Roberval balance to which the invention is shown applied by way of example.
Figure 3 shows a pair of suspended scales and figure 4 a detail section of my first
improvement for application thereto. Figures and 6 are a sectional elevation and
plan showing the application of my second improvement.
The same letters of reference indicate the same parts in all the figures.
The first part of the invention is illustrated in figures 1 and 2 as applied to a
balance of the Roberval type. a is the cushion which, in this example, is a spiral
spring. It is placed beneath a shoulder 6 on the vertical pivot c upon which the
scale pan is carried. The cushion a is located in a cavity in the cross-bar e which
carries the agate-bearings that rest on the knife edges g of the beam l. If only one
cushion be used, it would be placed beneath the pan on which the weights are placed,
but a similar cushion may be applied beneath each scale pan, especially when the
weights are placed indifferently on either.
Figures 3 and 4 illustrate the application of the invention to hauging scales. In
this case the spring cushions are interposed between the suspension rods of the
scale pans and the stirrups carrying the end centre bearings by which the pans are
hung on the end-centres of the beam. The spring cushion a is contained in a
cylinder having ears j or otherwise adapted for the attachment of the sus
pension links or frame of the scale pan, the spring being confined between the end
of the cylinder and a head k on a rod sliding through the end of the cylinder and
provided with a hook for attachment to the stirrup.
Figures 5 and 6 illustrate the mode of adjusting a Roberval balance. The beam?
is formed with a central annular rib or frame which carries the knife edge centres and
in which is mounted a screw m, said screw being in the horizontal plane of the beam
and lying across the centre of oscillation in a direction at about an angle of 45°
thereto. This screw is journaled stiffly at its ends in the beam so that it may be
revolved, but is incapable of longitudinal motion and upon it is placed a weight n
tapped to fit the screw and which is in contact, by its flat upper face with the under-
side of the top plate of the central part of the beam so that, the weight being thereby
prevented from turning, it will be traversed along the screw when the latter is
revolved which may be done by a turnscrew applied to a nick in one end of the
screw.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, I declare that what.I
claim is :-
1. The combination, with a weighing-scale or balance, of a spring or spring-cushion
interposed between the scale pan and its centre or point of support on the beam,
substantially as, and for the purpose specified.
2. In a balance of the Roberval type, the herein described means of adjustment,
consisting of a weight traversing upon a screw mounted in the horizontal plane of,

page_text: and at the centre of, the beam in a diagonal position so as to enable a very fine adjust-
ment to be obtained, substantially as described.
Dated this 10th day of May 1889.
C. H. BARTLETT,
By A. M. & Wm. Clark, Patent Agents, 53, Chancery Lane, London.