IMPROVEMENTS IN BALANCES OR SCALES FOR WEIGHING
Year: 1884

page_text: I JAMES MURDOCH NAPIER of York Road Lambeth in the County of Surrey
Engineer do hereby declare the nature of my invention for "IMPROVEMENTS IN
BALANCES OR SCALES FOR WEIGHING" to be as follows:-
My improvements have reference to balances or weighing scales which are
actuated in their disengagement for weighing and their replacement in preparation,
for the next weighing by power exerted by the operator or weigher.
The objects of my improvements in such balances are to render the operation of
weighing more easy and convenient and to ensure greater rapidity and accuracy.
I arrange and construct the scale pans so that on the scale-pan at one end of the
beam standard weights in convenient parts amounting in total to the heaviest
weight which it is intended to weigh are placed while on the other scale-pan is
placed a permanent counterpoise in convenient form which counterpoise is marle
sufficient to balance the whole of the standard part weights on the other end of the
beam or when weighing a load to balance the load weighed and such of the
standard part weights as will serve with it to balance the counterpoise. The
weight of the load is represented by the sum of the part weights which have been
removed from the scale pan and supplanted by the load. In combination with this
arrangement of scale pans counterpoise and standard part weights I employ two
levers each with balance weights operating with a roller against a suitably formed
cam the cams being fixed to a main shaft or spindle actuated by the weigher so
that by virtue of the forms given to the cams the one set of balance weights on
the one lever serves to balance the other set of balance weights except for a short
portion of the movement of the shaft during which the disengagement and replace-
ment of the weighing beam are effected at which times the weights on one of the
levers operate to raise and balance the weight of the scale pans with their contents
off the beam, and the beam itself if desired the cam in connection with the other
lever preventing for the time the weights on it from acting to balance the weights
on the other lever, thus the power which would otherwise be employed by the
weigher is reduced.
In order that the weigher may the more conveniently operate I arrange suitable
gearing connected with the main shaft or spindle so that it can be worked by
a cranked handle horizontally on the table of the balance which handle can be
turned with little effort owing to the operation of the levers and balance weights

page_text: already referred to both in the sense to put the balance into weighing and in the
reverse sense to return the balance to a state of rest ready for the exchange of the
load, the cams being formed suitably to take a part of a turn only in one direction
and to return to rest.
In combination with the above arrangements I use for the disengagement of my
improved balance grippers having a small holding power which are opened by a
cain action in connection with the main spindle soon after a first disengagement
of the beam has taken place and so form a second or fine disengagement when
the load and standard part weights with it happen to be equal or nearly equal to
the counterpoise.
In order to avoid the use of very small part weights I arrange an arm attached
to the pointer of the balance divided as may be desired and employ a weight which
can be placed upon the arm towards or from the centre operating by its leverage
to decrease or increase its effective weight as indicated by the divisions on the arm.
This weight when at its extreme outward position will complete with the standard
part weights on the scale-pan the quantity which is balanced by the counterpoise
and its value indicated at the point to which it may be withdrawn from that
position towards the centre in effecting a correct weighing will be added to the
part weights taken from the scale-pan and so together they will represent the
weight of the load or quantity which has been weighed.
To facilitate the adjustment of the balance for weighing I provide two lever
weights fitted to the pointer of the balance, the larger and less used of which
I place high up on the pointer and the smaller lower and very handy for use.
In adjusting the balance I place the whole of the standard part-weights on the
scale-pan and I put the weight which is on the arm referred to as fixed on the
pointer at its full outward position the part-weights and the value of the weight
on the arm referred to making up together the full quantity which can be weighed.
I then try a weighing when if the pointer stands at zero the balance is in weighing
order. If it moves to the right or left I regulate by the small lever weight on the
pointer and if necessary by the larger one also.
The lever weights turn on the pointer as an axis and are held in their position
by friction.

page_text: I JAMES MURDOCH NAPIER of York Road Lambeth in the County of Surrey
Engineer 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 :-
-
My improvements have reference to balances or weighing scales which are
actuated in their disengagement for weighing and their replacement in preparation
for the next weighing by power exerted by the operator or weigher.
The objects of my improvements in such balances are to render the operation of
weighing more easy and convenient and to ensure greater rapidity and accuracy.
I arrange and construct the scale pans so that on the scale-pan at one end of the
beam standard weights in convenient parts amounting in total to the heaviest
weight which it is intended to weigh are placed while on the other scale pan is
placed a permanent counterpoise in convenient form, which counterpoise is made
sufficient to balance the whole of the standard part weights on the other end of the
beam or when weighing a load to balance the load weighed and such of the
standard part weights as will serve with it to balance the counterpoise. The
weight of the load is represented by the sum of the part weights which have been
removed from the scale pan and supplanted by the load. In combination with this
arrangement of scale pans counterpoise and standard part weights I employ two
levers each with balance weights operating with a roller against a suitably formed
cam, the cams being fixed to a main shaft or spindle actuated by the weigher so
that by virtue of the forms given to the cams the one set of balance weights on the
one lever serves to balance the other set of balance weights except for a short
portion of the movement of the shaft during which the disengagement and replace-
ment of the weighing beam are effected, at which times the weights on one of the
levers operate to raise and balance the weight of the scale pans with their contents
off the beam, and the beam itself if desired, the cam in connection with the other
lever preventing for the time the weights on it from acting to balance the weights
on the other lever, thus the power which would otherwise be employed by the
weigher is reduced. In order that the weigher may the more conveniently operate
I arrange suitable gearing connected with the main shaft or spindle so that it can
be worked by a cranked handle horizontally on the table of the balance which
handle can be turned with little effort owing to the operation of the levers and
balance weights already referred to both in the sense to put the balance into
weighing and in the reverse sense to return the balance to a state of rest ready for
the exchange of the load the cams being formed suitably to take a part of a turn
only in one direction and to return to rest.
In combination with the above arrangements I use for the disengagement of my
improved balance, grippers having a small holding power which are opened by a
cam action in connection with the main spindle soon after a first disengagement of
the beam has taken place and so form a second or fine disengagement when the
load and standard part weights with it happen to be equal or nearly equal to the
counterpoise.

page_text: the weighing is completed the handle I' is turned in the reverse sense and the
parts return to the position indicated in the drawing.
Figure 4 represents an arrangement of mechanism for actuating grippers, such as
are shown in Figure 5 for disengaging the beam for weighing after the ordinary
disengagement has taken place serviceable in the case of fine weighings On the
main spindle I is fixed a disc f which has two pins fif fastened in it, these
actuate the lever f³ which at one end is loose on spindle I. and at the other end
has a pin which acts as a cam in the catch f* which vibrates on centre at f*.
Attached to lever and vibrating on the same centre is lever fo which has a
balance weight f' which serves to balance the other end of the lever and the
connecting rod f³ rising from it to the bell crank lever f. The rod f10 shown
broken off, serves to connect and give action to the gripper disengagement which is
shown on a large scale in figure 5. When the main spindle I is turned in the
direction of the arrow and after the first or ordinary disengagement for weighing
has taken place, the pin f* is forced against lever f³ and disengages it from the
catch lever f which falls forward by the action of spring f" until the lever ƒ°
at f" comes down on stop ƒ¹³ This movement acting through the connections
already described opens the grippers and releases the rod fi fig. 5 which is
supposed to be attached to a convenient part of the beam or to a hanger at the end
of it and to move endwise between the gripping jaws. When the reverse action is
given by the weigher the lever f³ fig. 4 is brought back into the catch in lever f*
by the pin f' and the grippers are closed to hold pin f 14 by spring f15 which is
permitted so to operate by the connections which reverse the action of the
connecting rod f10 when the play provided at its end where it is attached to the
grippers permits the spring f¹ to act to close the grippers.
13
14
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. Balances or scales having at one end of the scale beam a counterpoise and
at the other a scale pan carrying the load and part weights and having also
a graduated arm on the pointer with a moveable weight thereon the whole so
arranged that when the equipoise is effected the weight of the load may be
indicated by the value of the part weights removed from the pan plus a small
amount shown by the position of the moveable weight on the arm of the pointer.
2. Balances or scales in which the movement to and fro of a hand wheel, or hand
lever actuates a weighted lifting lever and a counterpoise lever the latter balancing
the lifting lever and parts connected therewith except at the moment when the
lifting lever operates to relieve the beam from the load.
3. Balances or scales in which the movement to and fro of a hand wheel or hand
lever in addition to placing the load on the beam and lifting it therefrom actuates
grippers effecting a second disengagement.
4. Balances or scales substantially as herein described and represented by the
annexed drawings.