IMPROVEMENTS IN THE CONSTRUC- TION OF WEIGHING MACHINES
Year: 1878

page_text: PROVISIONAL SPECIFICATION left by Adolfo Cozza at the Office of the
Commissioners of Patents on the 17th January 1878.
ADOLFO COZZA, of Orvietto, in the Kingdom of Italy, but at present residing at
Queen Street Place, in the City of London. "IMPROVEMENTS IN THE CONSTRUC-
TION OF WEIGHING MACHINES."
"
This Invention relates mainly to improvements on the Invention of "An Improved
Construction of Weighing Machine," for which I obtained Letters Patent bearing
date June 26th 1877, No. 2648, the objects being,-
First. To release the platform supports of the weight of the platform when the
machine is not in use.
And, Secondly. To indicate with accuracy and at any convenient distance from
the machine the weight of the load placed upon the platform.
In this, as in the former case, the weight of the platform and its load is sustained
by a yielding support, which is itself maintained in position preferably by hydraulic
pressure. In the pressure chamber or cylinder is fitted a sliding rod, which consti-
tutes a piston, the outer end of which forms the yielding support for the inclined
rockers which carry the platform. The inner end of this rod is surrounded by an
annular piston, which slides freely thereon, and bears against a shoulder on the rod.
A flexible diaphragm secured to the pressure chambers covers the inner faces of
the two concentric pistons, and serves to transmit the pressure put upon the water
in the chamber to both pistons, and cause them to travel outwards. This outward
movement is for the purpose of raising the platform to its position for weighing, its
normal position being on the base of the machine. This position not only relieves
the V edges of the rockers from its weight, but also provides for the platform, con-
stituting a firm support for any traffic that may pass over it when it forms a portion
of a weighbridge.
The hydraulic pressure chamber I connect by a pipe with a pressure gauge so
arranged that when pressure is applied to raise the platform without a load the
indicator hand will move round to zero. This pressure I apply by means of a
pump or its equivalent, any excess of pressure applied to the water having no effect
on the indicator, but serving simply to raise the platform. This pressure, whatever
its amount, must be maintained during the operation.

page_text: By placing a load on the elevated platform the platform will be depressed, the
supporting piston yielding to this pressure. This back movement of the piston will
increase the pressure in the hydraulic pressure chamber exactly in proportion to the
weight of the load, which weight will be indicated on the gauge. When the weight is
ascertained the pressure of the pump or its equivalent is taken off, and the platform
is allowed to drop and rest on the base of the machine, as before.
As a modification of the above-described apparatus I propose to use a steelyard
in place of the gauge, and a weighted lever, which will act automatically in place
of the pump; thus, in connection with the hydraulic pressure chamber, I employ
two floating pistons, which are free to rise and fall under the varying pressures of
the water. These I connect the one with a steelyard arm, and the other with a
weighted lever, which is provided with a self-acting catch for locking into a sector
rack. This lever is weighted so as to counterbalance the platform, and when
unlocked it will drop and raise the platform to its weighing position. The spring
catch will then prevent the lever from rising under the pressure of a load put upon
the platform. On placing a load on the raised platform the steelyard will come
into action, and indicate in the usual manner the weight of the load.
When the weighing is effected the weighted lever is to be unlocked and raised to
allow of the platform returning to its normal position, and the spring catch will
then secure the lever in its raised position.
An important advantage of these arragements is that any waste of water from
leakage or otherwise will not effect the accuracy of the weighing.
It may here be remarked that the means described for indicating the weight of
the load at a distance from the weighing machine may be used in connection with
any of the well-known construction of weighbridges.