IMPROVEMENTS IN SAFETY VALVES FOR STEAM BOILERS
Year: 1879

page_text: LETTERS PATENT to William Eaves, of the Atlas Works, Sheffield, in the
County of York, Engineer, for the Invention of "IMPROVEMENTS IN SAFETY
VALVES FOR STEAM BOILERS."
Sealed the 29th August 1879, and dated the 2nd April 1879.
PROVISIONAL SPECIFICATION left by the said William Eaves at the Office
of the Commissioners of Patents on the 2nd April 1879.
WILLIAM EAVES, of the Atlas Works, Sheffield, in the County of York. *IM-
PROVEMENTS IN SAFETY VALVES FOR STEAM BOILERS,"
My Invention has reference to improvements on the Invention described in the
Specification of a Patent granted unto me, and bearing date 3rd January 1878
(No. 41), the object of which improvements is to make what is termed a good "lip
opening" for the valve, and thereby controlling or limiting the steam pressure, so
as to prevent any excess of pressure inside the boiler beyond that at which the valve
is set to rise.
-
And my Invention consists in making the concave "centre piece" described in
the Specification above referred to of such a form as to cover a larger portion of
the upper surface of the ball, and of sufficient width to form a projection from the
ball for the escaping steam to play against, and also in forming a dish or cup round
the lower surface of the ball, leaving an annular space between such dish or cup
and the surface of the ball sufficiently large to allow of the free escape of the surplus
steam.
By means of this arrangement the escaping steam is directed on to the before-
named projection, and acting thereon with great force causes the valve to
be lifted further from its seat, thereby causing a greater "lip opening" than
would otherwise occur, and so preventing any further increase of pressure in the
boiler.
The projecting bottom surface of the "centre piece" is bevilled slightly, but the
amount of bevil can be varied as required, in order to regulate or control the period
at which the extra "lip opening" shall be caused to come into operation.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said William Eaves in the Great Seal Patent Office on the 26th
September 1879.
จ
WILLIAM EAVES, of the Atlas Works, Sheffield, in the County of York, Engineer.
"IMPROVEMENTS IN SAFETY VALVES FOR STEAM BOILERS."
My Invention of "Improvements in Safety Valves for Steam Boilers" has
reference to improvements on the Invention described in the Specification of a
Patent granted unto me, and bearing date third January, One thousand eight
hundred and seventy eight (No. 41), the object of which improvements is to make
what is termed a good "lip opening" for the valve, and thereby controlling or
limiting the steam pressure, so as to prevent any excess of pressure in the boiler
beyond that at which the valve is set to rise.
And my Invention consists in making the concave "centre piece" described in
the Specification above referred to of such a form as to cover a larger portion of
the upper surface of the ball, and of sufficient width to form a projection from the
ball for the escaping steam to play against, and also in forming a dish or cup round
the lower surface of the ball, leaving an annular space between such dish or cup
and the surface of the ball, sufficiently large to allow of the free escape of the surplus
steam.
By means of this arrangement the escaping steam is directed onto the before
named projection, and acting thereon with great force causes the valve to
be lifted further from its seat, thereby causing a greater "lip opening" than
would otherwise occur, and so preventing any further increase of pressure in the
boiler.
The projecting bottom surface of the "centre piece" is bevilled slightly, but the
amount of bevil can be varied as required, in order to regulate or control the
period at which the extra "lip opening" shall be caused to come into operation.
Having thus stated the nature of the said Invention, I will proceed to describe
more particularly in what manner the same is to be performed by the aid of the
accompanying Drawing, in which are represented the improvements above
referred to.
DESCRIPTION OF THE DRAWING.
The Figure is a vertical section of the valve; A is the valve or ball made of brass
or other suitable material; B is the hard seating made of steel or other suitable
substance or material; C is the concave "centre piece," which is made of such a
form as to cover a larger portion of the upper surface of the ball than in the case
of my former Patent above referred to, and of sufficient width to form a projection
from the ball at c for the escaping steam to play against. This "centre piece" is
lined with soft metal or other suitable material adapted to prevent injury to the
ball. The projecting bottom surface of the "centre piece" is bevilled slightly as
shewn, and the amount of bevil can be varied as required, in order to regulate or
control the period at which the extra “lip opening" shall be caused to come into
operation.
D is a dish or cup formed round the lower surface of the ball, leaving a space
between such dish or cup and the surface of the ball sufficiently large to allow of
the free escape of the surplus steam. The curve of the dish or cup is not concentric
or parallel with the surface of the ball, but is so formed as to give a greater distance
between the inside of the cup and the outside of the ball at the top of the space
than at the bottom thereof, which will have the effect of enabling the steam to
escape more freely.
By means of the above described arrangement the steam as it escapes directed
on to the bevilled projection at c, and acting thereon with great force causes the

page_text: valve to be lifted further from its seat B, thereby causing an increased " lip
opening," and so preventing any fuurther increase of pressure in the boiler. The
other parts of the valve are or may be similar to those belonging to the valve
described under my former Patent.
Having thus described the nature of the said Invention, and in what manner the
same is to be performed, I would remark that I do not claim any of the parts of the
valve above described and referred to otherwise than as used in combination with
the improvements on my former Patent herein described, but what I do claim as of
my present Invention is, the improved form of the concave "centre piece" combined
with the dish or cup, in order to provide a good "lip opening" for the valve, as
herein before described.
.
In witness whereof, I, the said William Eaves, have hereunto set my hand
and seal, this Twenty fifth day of September, in the year of our Lord One
thousand eight hundred and seventy nine.
Witness,
JOHN C. DUNCAN,
Atlas Works, Sheffield,
Secretary of John Brown & Co., Limd.
WILLIAM EAVES. (L.S.)