IMPROVEMENTS IN THE CONSTRUCTION OF WEIGHING MACHINES AND SCALE BEAMS
Year: 1876

page_text: LETTERS PATENT to William Beilby Avery, of Birmingham, in the County of
Warwick, for the Invention of "IMPROVEMENTS IN THE CONSTRUCTION OF
WEIGHING MACHINES AND SCALE BEAMS."
aled the 18th July 1876, and dated the 22nd April 1876.
PROVISIONAL SPECIFICATION left by the said William Beilby Avery at the
Office of the Commissioners of Patents on the 22nd April 1876.
WILLIAM BEILBY AVERY, of Birmingham, in the County of Warwick. "IM-
PROVEMENTS IN THE CONSTRUCTION OF WEIGHING MACHINES AND SCALE BEAMS."
The object of this Invention is so to construct scale beams and the beams or levers
of counter, platform, and other weighing machines and steelyards as to make them
perfectly accurate weighing instruments without the necessity for manipulating
the knife edges of such scale beams or beams or levers of weighing machines or
steelyards after having once been formed and hardened, which has heretofore
been an unsatisfactory, tedious, and costly operation.
According to my Invention I drill round holes through the beams to suit the
various positions of the centres, the centres I cut from circular pins and fit into
the drilled holes. I then harden the centres and effect their true adjustment, not
by interfering with the hardened knife edges of the V centres, that is to say,
altering their position by scraping or rubbing them with emery cloth or stone as
heretofore, but by turning them upon their axes, so as to make them perfectly correct
or true one with the other, the result being to produce a inuch more rapidly adjustable
and accurate weighing instrument than can be produced by the present process.
The centres are fixed in proper position preferably by the following methods:-
1st. The centres are formed from conical shaped pins, and the holes in the beam
being rymered to the same taper; the centres are tightened by means of clamping
nuts or taper keys and slots. 2nd. The centres are formed from straight round
pins with a shoulder to one side; the beam is drilled exactly to fit such pins and
centres, and is tightened against the shoulder of the pin by means of clamping nuts
and screws, or slots and taper cotters. 3rd. The centres are formed from straight
round pins drilled transversely, care being taken that the transverse holes are
perfectly true with the V centres. The beams are drilled and fitted thereto and drilled
[Price 6d 1

page_text: tranversely, likewise true with the end knife edges or similar holes for centre pins,
and when perfectly adjusted upon axes the transverse holes in both centre and
beam are rymered taper, and a round taper pin driven in.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said William Beilby Avery in the Great Seal Patent Office on the 20th
October 1876.
"IM-
WILLIAM BEILBY AVERY, of Birmingham, in the County of Warwick.
PROVEMENTS IN THE CONSTRUCTION OF WEIGHING MACHINES AND SCALE BEAMS."
The object of this Invention is so to construct scale beams and the beams or
levers of counter, platform, and other weighing machines and steelyards as to make
them perfectly accurate weighing instruments without the necessity for manipu-
lating the knife edges of such scile beams or beams or levers of weighing machines
or steelyards after they have once been formed and hardened, which has heretofore
been an unsatisfactory, tedious, and costly operation.
According to my Invention I drill round holes through the beams to suit the various
positions of the centres, and the centres I cut from circular pins and fit into the drilled
holes, I then harden the centres and effect their true adjustment, not by interfering
with the hardened knife edges of the V centres, that is to say, altering their position
by scraping or rubbing them with emery cloth or stone as heretofore, but by turning
them upon their axes so as to make them perfectly correct or true one with the
other, the result being to produce a much more rapidly adjustable and accurate
weighing instrument than can be produced by the present process.
The centres are fixed in proper position preferably by the following methods:---
First. The centres are formed from conical shaped pins, and the holes in the beam
being rymered to the same taper, the centres are tightened by means of clamping
nuts or taper keys and slots. Second. The centres are formed from straight round
pins with a shoulder to one side; the beam is drilled exactly to fit such pins and
centres, and is tightened against the shoulder of the pin by means of clamping nuts
and screws or slots and tapper cotters. Third. The centres are formed from straight
round pins drilled transversely, care being taken that the transverse holes are
perfectly true with the V centres. The beams are drilled and fitted thereto and
drilled transversely, likewise true with the end knife edges or similar holes for
centre pins, and when perfectly adjusted the transverse holes in both centre and
beam are rymered taper, and a round taper pin is driven in.
In the accompanying Drawings illustrations are given of the several methods
above described of carrying out the object of my Invention.
In Sheet I., Fig. 1 shews in side elevation, and Fig. 2 in sectional plan a scale
beam fitted with adjustable centres, A being the middle centre on which the beam
oscillates, and B, B, the end centres from which the scales are suspended.
Figures 3, Sheet II., shew one mode of fitting a double V-edged centre to its beam..
In this case the centre is made of a steel più coned as at a, and brought to a V
shape at its opposite ends as at b, b. The hole in the beam C for receiving the
centre is coned to fit the conical portion of the pin. On the smaller end of the
cone a a thread is cut to receive a clamping nut d, by tightening up which the pin
is drawn into its conical seat and held firmly in position. This is done when the
pin has been adjusted axially so as to bring its edges into a vertical position
while the beam is supported in a horizontal position. If by any accident this
position of the knife edges relatively to the beam is disturbed it may be readily
corrected by first slackening the clamping nut d. Instead of using a clamping nut
for fastening the centre to its beam, a taper key e may be employed, as shewn at
Figures 4. Figures 5 show a coned centre pin with a single V edge suitable for
a weighing machine beam, a clamping nut being used to fix the cone a in its

page_text: seat in the beam C. Figures 6 shew a taper key e used in place of the clamping
nut for securing the coned pin with its V edge b in position in the beam C. Instead
of relying on the cone for making close contact with the beam I sometimes form
the centre with a shoulder as at F, Figure 7, the face of which may by means of
a nut or key be caused to bind tightly against the beam. This shoulder may have
a flat face, as at Figure 7, or a coned face, as at Figures 8 and 9. Such coned face
entering a corresponding hollow in the beam, and being held securely therein by a
key or a nut applied to the centre pin. Instead of the key or nut a binding screw
may be used, as at Figures 10, to fix the centre when properly adjusted in the beam.
Figures 11 illustrate the mode above described of securing the centre by means of
a taper pin which passes through a taper hole drilled vertically through the beam
and the centre after adjustment. Figures 12 shew a centre suitable for a box
end beam or the beams or levers of platform or such like weighing machines, the
knife edge being made in the middle of the pin, and dividing into two portions the.
cone or bearing parts which by the aid of a binding nut or a key serves to secure
the centre in place. This centre is shewn in position at B, Figures 1 and 2.
Having now set forth the nature of my Invention of "Improvements in the
Construction of Weighing Machines and Scale Beams," and explained the manner of
carrying the same into effect, I wish it to be understood that under the above in
part recited Letters Patent I claim, constructing and applying the centres of
weighing machines and scale beams in the manner and for the purpose above set
forth.
In witness whereof, I, the said William Beilby Avery, have hereunto set my
hand and seal, the Twenty-seventh day September, in the year of our Lord,
One thousand eight hundred and seventy-six.
WILLIAM BEILBY AVERY. (L.S.)