IMPROVEMENTS IN HYDRAULIC APPARATUS FOR THE REPRODUCTION AT A DISTANCE OF CHARACTERS, SIGNS, DELINEATIONS AND MOTIONS
Year: 1884

page_text: I Theodore Tubini of 29 Ladbroke Gardens, Notting Hill in the County of
Middlesex, Gentleman do hereby declare the nature of the said invention for
IMPROVEMENTS IN HYDRAULIC APPARATUS FOR THE REPRODUCTION AT A DISTANCE
OF CHARACTERS, SIGNS, DELINEATIONS AND MOTIONS to be as follows:--
"
My Invention relates to an improvement in the hydraulic writing apparatus for
the reproduction at a distance of autographic or other characters, signs and motions
of the kind which forms the subject of a previous application for Letters Patent
made by me and dated June 28th 1884 No. 9550 and it has for its object to enable
the difference of level between the transmitting and receiving stations to be
compensated for, to render the working of the apparatus independent of atmo-
spheric pressure, and to obtain the same results as when working with closed
circuits as described in my aforesaid application, but without the necessity of
duplicating the tubes connecting the transmitting and receiving instruments.
According to my Invention I provide each instrument with a compressed air
chamber or its equivalent which is placed in communication with the duplicate
pair of cylinders described at the latter part of my aforesaid application. This
chamber is charged to a suitable pressure to afford the requisite certainty of action
and the difference of pressure between the air chambers of the transmitting and
receiving apparatus corresponds to the height of the column of liquid between the
two stations. The plungers of the instrument at the lower level are thus relieved
of the excessive pressure due to the difference of altitude.
As an equivalent for a compressed air chamber a mercurial or other column
might be used but with less advantage.
.
In either case this method of working and of compensation for difference of level
is not limited to apparatus having straight cylinders with plungers as described
in my aforesaid application but is also applicable to apparatus having segmental
cylinders with oscillating pistons.

page_text: COMILELE
'I THEODORE TUBINI of 29 Ladbroke Gardens, Notting Hill in the County of
Middlesex, Gentleman, do hereby declare the nature of my invention for IMPROVE-
MENTS IN HYDRAULIC APPARATUS FOR THE REPRODUCTION AT A DISTANCE OF
CHARACTERS, SIGNS, DELINEATIONS AND MOTIONS and in what manner the same is
to be performed, to be particularly described and ascertained in and by the
following statement :—
My Invention relates to an improvement in the hydraulic writing apparatus for
the reproduction at a distance of autographic or other characters, signs and motions
of the kind which forms the subject of a previous application for Letters Patent
made by me and dated June 28th 1884 N° 9,550 and it has for its object, in the
case of a single acting instrument having only one pair of cylinders, to enable the
difference of level between the transmitting and receiving stations to be com-
pensated for, to render the working of the apparatus independent of atmospheric
pressure, and to obtain the same results as when working with a complete hydraulic
circuit as described in my aforesaid application, but without the necessity of
duplicating the tubes connecting the transmitting and receiving instruments.
According to my invention I provide each instrument with a compressed air
chamber or its equivalent which is placed in communication with the pair of
cylinders of the single acting instrument referred to in my aforesaid application.
This chamber is charged to a suitable pressure to afford the requisite certainty of
action and the difference of pressure between the air chambers of the transmitting
and receiving apparatus corresponds to the vertical height of the column of liquid
between the two stations. The plungers of the instrument at the lower level are
thus relieved of the excessive pressure due to the difference of altitude.
As an equivalent for a compressed air chamber a mercurial or other liquid
column might be used or weights may be applied to counterbalance the pressure
as hereafter described.
Reference is to be had to the accompanying drawings forming part of this
specification in which figure 1 shows the application of compressed air, and
figures 2 and 3 the use of weights to counterbalance the pressure.
A A¹ are the bydraulic cylinders, a a¹ their plungers connected by links c to a
beam & pivoted at d and having a third arm g carrying the pencil p all as in the
specification of my aforesaid application. In this case the guide for the centre of
motion of the beam & is the plunger k of an air cylinder / parallel to cylinders A. A¹
and acting in the opposite direction thereto, this cylinder being in communication
with a compressed air chamber m in which air is compressed by means of a piston
or otherwise sufficiently to make the pressure on the plunger k exactly counter-
balance the pressure on the plungers à due to the difference of level between the
transmitting and receiving instruments.
'
In figures 2 and 3 the pressure on each plunger is counterbalanced by a weight w
hung by a cord o passing over a guide pulley and attached to a lug on the corre-
sponding plunger, the weight being variable so that it may be made to exactly
counterbalance the liquid column acting on said plunger,

page_text: This method of working & of compensation for difference of level is not limited
to apparatus having straight cylinders with plungers as described in my aforesaid
application but is also applicable to apparatus having segmental cylinders with
oscillating pistons.
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
The employment in combination with an hydraulic writing apparatus of the
kind herein described, of compressed air or a mercurial or other liquid column or
weights applied to act on the plungers of the instrument in opposition to the
pressure due to the difference of altitude between the two instruments and
compensating such pressure substantially in the manner specified.