AN IMPROVED PRESSURE INDICATOR FOR TAKING CONTINUOUS DIAGRAMS
Year: 1876

page_text: LETTERS PATENT to William Robert Lake, of the Firm of Haseltine, Lake,
& Co., Patent Agents, Southampton Buildings, London, for the Invention of
"AN IMPROVED PRESSURE INDICATOR FOR TAKING CONTINUOUS DIAGRAMS."
A communication from abroad by De Hennault, Brothers, and Lucien Guinotte,
all of Mariemont, Belgium.
Sealed the 13th April 1877, and dated the 1st November 1876.
PROVISIONAL SPECIFICATION left by the said William Robert Lake at the
Office of the Commissioners of Patents on the 1st November 1876.
WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake, & Co., Patent Agents,
Southampton Buildings, London. "AN IMPROVED PRESSURE INDICATOR FOR TAKING
CONTINUOUS DIAGRAMS." A communication.
This Invention relates to an apparatus for indicating pressure, and comprises a
small cylinder open at its upper end, and provided with a tubulure and cock for
communicating at the bottom with the apparatus containing the steam or gas to be
experimented with. A solid piston within this cylinder is controlled or actuated by
a spring, and according as the pressure of the gas or steam is greater or less than
that of the atmosphere the piston rises or falls, compressing or extending the said
spring.
The piston rod acts upon a jointed piece, and causes a pencil to describe a certain
line on a sheet of paper rolled upon a cylinder, which cylinder is rotated by means
of a pulley and special gearing, which form one of the principal features of this
Invention.
The gearing is controlled by a pulley, upon which is rolled a strip of steel attached
for example to the cross head of the piston. When the piston advances to the end
of its course a spring is compressed, and when the piston returns the spring is
relaxed, and thus causes a contrary movement, but the roll upon which the paper is
wound turns always in the same direction, which is owing to the movement of the
pawl which is placed in the interior of the gearing to fasten the paper.
A brake is
placed on the aforesaid cylinder, and on one of the gear wheels I place two small
pieces, which in turning come in contact with an inclined plane that causes the
marking by the pencil of the dead points of the engine or machine. Another pencil
marks the atmospheric line.

page_text: A is the cylinder containing the piston which indicates the pressure; B is a
movable pencil to trace or mark the pressure upon the paper; C is a cylinder upon
which the said paper is coiled; D is a copper blade or strip over which passes the
paper in one thickness from the cylinder C, and which is traced or marked by the
pencils B, L, M; E is a transmission pulley to the engine, applied on the axis of the
worm V; F is a box containing the spring for turning back the pulley E; G is a
worm wheel cut right and left, and which contains the pawl that causes the paper
cylinder or rollers to turn in the same direction; K shows inclined planes, against
which the pieces S abut; L is a pencil marking the dead points of the engine; M is
a pencil which marks the atmospheric line; I is a brake to regulate the rotation of
the cylinder C. The endless screw or worm V cut from right to left serves to put
in motion the worm wheel G, which gives the movement whereby the continuous
diagrams are obtained; W is a hinge, which permits the brake I to be raised for
removing from the apparatus the cylinder C at each operation to replace the paper
that has been used.
The piston rod acts upon a jointed piece shewn in the Drawing, and causes a
pencil B to describe a certain line on the sheet of paper rolled upon the cylinder C,
which cylinder is rotated by means of a pulley and special gearing, the combination
of which is one of the principal features of this Invention. The said sheet of paper
passes over a strip of copper D (placed at a short distance from the cylinder to
facilitate the rolling of sufficient paper for the diagrams). This strip of copper is
provided solely that there may be only one thickness of paper where the pencils
press.
The screw V and the gearing are controlled by the pulley E, upon which is rolled
a strip of steel attached, for example, to the cross head of the piston. In the box F
is a spring when the piston advances the said spring is compressed to the end of
the piston's course, and when the piston returns the spring is relaxed, and thus
causes a contrary movement, but the cylinder upon which the paper is wound turns
always in the same direction, which is owing to the movement of the pawl which is
placed in the interior of the gearing G to fasten the paper. A brake I is placed on
the aforesaid cylinder C, and on one of the gear wheels G I place two small pieces S,
which in turning come in contact with an inclined plane K that causes the marking
by the pencil L of the dead points of the engine or machine. Another pencil M
marks the atmospheric line.
Having thus fully described the said Invention as communicated to me by my
foreign correspondents, and the manner of performing the same, I wish it understood
that I claim, the apparatus for obtaining continuous diagrams from steam, water,

page_text: gas, air, and other motors, which apparatus is constructed as shown in the accom-
panying Drawing, or with one or other of its parts modified in construction but
serving the purpose of the said Invention, as above set forth.
In witness whereof, J, the said William Robert Lake, have hereunto set my
hand and seal, this Thirtieth day of April, in the year of our Lord One
thousand eight hundred and seventy-seven.
W. ROB. LAKE. (L.S.)