Improvements in Beam Scales or Balances.
Year: 1893

page_text: Date of Application, 20th July, 1893
Complete Specification Left, 19th Apr., 1894-Accepted, 19th May, 1894
PROVISIONAL SPECIFICATION.
Improvements in Beam Scales or Balances.
We, WILLIAM CHRISTOPHER FANNER, and HENRY ELFICK, both of
13 Farringdon Road, in the County of London, Balance Manufacturers, do
hereby declare the nature of this invention to be as follows :-
The object of this invention is to construct a weighing instrument of precision
intermediate between an ordinary weighing beam and a fine balance working on
plane bearings at centre and ends.
The centre knife edge is made of a slightly tapered prism of steel and is driven
firmly into a triangular hole in the beam (after the edge has been truly set) and
remains untouched in the adjustment, as it is practically impossible to adjust by the
centre for whether the adjustment be for centre of gravity, centre of oscillation or
equality of arm whatever alteration is made there is doubled by taking from one
and adding to the other. Therefore this operation can only be done one end at a
time to a fixed centre, and to attain this purpose the construction is as follows:-
The two end knife edges have rectangular sides and bases whilst their tops are
brought to an acute angle to form the knife edge. They have vertically elongated
holes through them parallel to the beam by which they are fixed to it.
The beam ends are made with planes upon which the knife-edges are supported
and these are held in position by screws through the elongated holes-this plan
affords a ready means of fitting, fixing and adjusting as to transverse parallelism,
horizontal parallelism or for getting the end knife-edges in the line of the centre of
gravity or for equalizing the length of arm, without any alteration of the knife-
edge after it has been set on a true surface.
The suspending shackle in which the beam works, is furnished with two bearing
blocks of steel having transverse triangular grooves in their upper faces to receive
the centre knife edge of the bean. Two opposite sides and the bottom of each
bearing block are grooved to receive the edges of a slot in the shackle in which the
block fits. The inner sides of the slots are formed to an obtuse angle and the
corresponding sides of the bearing blocks are made slightly more obtuse so that
the pressing screws which are brought to bear on the opposite sides of the blocks
shall always have the tendency to force them down on to their bases. This
prevents any vibratory motion which would be liable to give an uncertain action.
The outer sides of the slots in the shackle are faced with steel and form abutments
for the ends of the centre knife edge which are brought to blunt points, a small
lateral play being allowed.
The suspending shackles at each end of the beam carry steel bearing blocks.
Each of these blocks has a transverse triangular groove in its bottom to receive
the knife edge on the beam and the two ends are grooved to fit the edges of the slot
in the shackle and is held in position by a screw through the top of the shackle.
The outer sides of which are faced with steel for abutments as described for the
centre shackle and are so formed that they cannot fall off, unless moved considerably
beyond the radius of motion in which the beam oscillates.
Dated this 20th day of July 1893.
WM. C. FANNER.
HENRY
ELFICK.

page_text: Dalautes.
We, WILLIAM CHRISTOPHER FANNER, and HENRY ELFICK, both of
13 Farringdon Road, in the County of London, Balance Manufacturers, 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 :--
The object of this invention is to construct a weighing instrument of precision
intermediate between an ordinary weighing beam and a fine balance working on
plane bearings at centre and ends.
The centre knife edge is made of a slightly tapered prism of steel and is driven
firmly into a triangular hole in the beam (after the edge has been truly set) and
remains untouched in the adjustment, as it is practically impossible to adjust by the
centre for whether the adjustment be for centre of gravity, centre of oscillation or
equality of arm whatever alteration is made there is doubled by taking from one
and adding to the other. Therefore this operation can only be done one end at a
time to a fixed centre, and to attain this purpose the construction is as follows:-
The two end knife edges have rectangular sides and bases whilst their tops are
brought to an acute angle to form the knife edge. They have vertically elongated
holes through them parallel to the beam by which they are fixed to it.
The beam ends are made with planes upon which the knife edges are supported
and these are held in position by screws through the elongated holes-this plan
affords a ready means of fitting, fixing and adjusting as to transverse parallelism,
horizontal parallelism or for getting the end knife edges in the line of the centre of
gravity or for equalizing the length of arm, without any alteration of the knife-edge
after it has been set on a true surface.
The suspending shackle in which the beam works, is furnished with two bearing
blocks of steel having transverse triangular grooves in their upper faces to receive
the centre knife edge of the beam. Two opposite sides and the bottom of each
bearing block are grooved to receive the edges of a slot in the shackle in which the
block fits. The inner sides of the slots are formed to an acute angle and the
corresponding sides of the bearing blocks are made slightly less acute so that a
the pressing screws which are brought to bear on the opposite sides of the blocks
shall always have the tendency to force them down on to their bases. This
prevents any vibratory motion which would be liable to give an uncertain action.
The outer sides of the slots in the shackle are faced with steel and form abutments
for the ends of the centre knife edge which are brought to blunt points, a small
lateral play being allowed.
The suspending shackles at each end of the beam carry steel bearing blocks.
Each of these blocks has a transverse triangular groove in its bottom to receive the
knife edge on the beam and the two ends are grooved to fit the edges of the slot in
the shackle and is held in position by a screw through the top of the shackle, the
outer sides of which are faced with steel for abutments as described for the
centre shackle and are so formed that they cannot fall off, unless moved
considerably beyond the radius of motion in which the beam oscillates.
DESCRIPTION OR TUR DRAWING

page_text: Figures 1 to 4 are half size and Figures to 9 are full size views of some of
the parts.
a is the beam and the centre knife edge, the latter is shown separately at
Figure 5. cc are the end kuife edges shown separately in side and end elevation
at Figures 6. d is the shackle by which the beam is suspended and e are the
bearing blocks in it, these are shown separately in end elevation and central section
at Figures 7. Figure 8 shews a section of the lower part of the shackle with the
blocks in place. fare plates of steel let into the shackle. y are the shackles at
the ends of the beam and are the bearing blocks in them, these are shown in
elevation and central section at Figures 9. The shackles 9 have plates of steel let
into them similar to the plates f of the shackle d.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what we
claim is :-
1. Notching the ends of the beam and securing the end knife edges to it by
screws in a line with it substantially as described.
2. Making the centre knife edge slightly taper and securing it to the beam by
driving substantially as described.
3. The method of securing the blocks e to the shackle d substantially as
described.
4. Inserting plates of steel in the sides of the shackles to form abutments for the
ends of the knife edges substantially as described.
5. Beam scales or balances substantially as described and shown in the
drawings.
Dated this 18th day of April 1894.
W. C. FANNER.
HENRY ELFICK.