IMPROVEMENTS IN SLIDE VALVES
Year: 1881

page_text: LETTERS PATENT to Cesare de Lucia, of Naples, Italy, Managing Director of
Maresca and Company, for an Invention of " IMPROVEMENTS IN SLIDE
VALVES."
PROVISIONAL SPECIFICATION left by the said Cesare de Lucia at the
Office of the Commissioners of Patents on the 24th August 1881.
CESARE DE LUCIA, of Naples, Italy, Managing Director of Maresca and
Company. "IMPROVEMENTS IN SLIDE VALVES."
This Invention relates to balanced slide valves for steam and other fluid pressure
engines. It consists in providing the cover of the valve chest with a cylinder open
towards the valve, and containing a piston connected with the back of the valve by
a link or links, preferably two in number, the area of the piston being sufficient to
counterbalance the whole or a considerable part of the fluid pressure acting on the
back of the slide valve. provide the piston with a suitable metallic packing,
and the cylinder with a cover which may be perforated for admitting air to the
top of the piston. The links connecting the valve with the piston are preferably
hinged at one end to eyes cast on the back of the valve, and at the opposite end to
a cross beam attached to the end of a bolt or spindle passing through the bottom
of the hollow piston, and secured on the other side by a screw nut. The valve
may otherwise be of any ordinary design.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Cesare de Lucia in the Great Seal Patent Office on the 24th February
1882.
CESARE DE LUCIA, of Naples, Italy, Managing Director of Maresca and
Company. "IMPROVEMENTS IN SLIDE VALVES."
My Invention relates to balanced slide valves for steam and other fluid pressure
engines. It consists in providing the cover of the valve chest with a cylinder
open towards the valve, and containing a piston connected with the back of the
valve by a link or links, preferably two in number, the area of the piston being
sufficient to counterbalance the whole or a considerable part of the fluid pressure
acting on the back of the slide valve. I provide the piston with a suitable
metallic packing, and the cylinder with a cover which may be perforated for
admitting air to the top of the piston. The links connecting the valve with the
piston are preferably hinged at one end to eyes cast on the back of the valve, and
at the opposite end to a cross beam attached to the end of a bolt or spindle passing
through the bottom of the hollow piston, and secured on the other side by a screw
nut. The valve may otherwise be of any ordinary design.
In the accompanying Drawing which illustrates my Invention, V, VI, VII, VII,
is a slide valve which differs from those frequently used for locomotives by the
addition of four eyes 0, 0¹, at the back.
A, A³, is the valve rod.
P, P, P, P, is the piston for balancing the slide valve. It is movable in the
cylinder formed in the cover of the valve chest, and provided with an ordinary
metallic packing ring I, I'. The back of the slide valve is connected with the
piston by two rods B, B¹, pivoted at one end to the four eyes 0, 0¹, and at the
other end to the beam G, G¹. The latter is secured at C to the eyebolt Pº passing
through the bottom of the piston, and provided with a nut D, as shown.
E, E, is the cover of the valve chest; F, F1, the cylinder cover screwed to the
top end of the cylinder, and having a small hole H in the centre to establish
communication with the atmosphere. The metallic packing ring is lubricated by
an ordinary oil cup fixed to the cover of the valve chest. It may be replaced by
other packings. The steam pressure on the bottom of the piston balances a part of
the steam pressure on the back of the slide valve, the resulting pressure depending
on the difference between the areas of the two exposed surfaces.
Instead of two rods B, B¹, one rod or a universal joint or any other suitable
device may be used for connecting the piston with the slide valve.
CLAIMS.
1. The combination of the movable hollow piston P, P¹, P", P¹¹¹, with a
cylinder R, R¹, attached to the valve chest, cover F, F¹, and means for connecting
the piston to the slide valve.
2. The combination of piston P, P', P, P, with packing ring I, I', cylinder R, R¹,
cover F, F, bolt Po, and means for connecting it with the back of the slide valve.
3. The combination of piston P, P1, P", p¹¹, cylinder R, R², cover F, F', bolt Pº,
beam G, G¹, rods B, B', and eyes 0, 0¹.
The whole substantially as described and illustrated.
In witness whereof, I, the said Cesare de Lucia, have hereunto set my hand
and seal, this Twentieth day of February, A.D. 1882.
CESARE
LALA