IMPROVEMENTS IN THE CONSTRUCTION OF SAFETY VALVES
Year: 1873

page_text: LETTERS PATENT to Peter Samson, of 27, Belmont Hill, Lewisham,
in the County of Kent, Engineer, and William Parker, of
Laburnum Villa, Rushey Green, Catford, in the County of Kent,
Engineer, for the Invention of "IMPROVEMENTS IN THE CONSTRUCTION
OF SAFETY VALVES."
Sealed the 13th March 1874, and dated the 19th December 1873.
PROVISIONAL SPECIFICATION left by the said Peter Samson and
William Parker at the Office of the Commissioners of Patents,
with their Petition, on the 19th December 1873.
We, PETER SAMSON, of 27, Belmont Hill, Lewisham, in the County
of Kent, Engineer, and WILLIAM PARKER, of Laburnum Villa, Rushey
Green, Catford, in the County of Kent, Engineer, do hereby declare the
nature of the said Invention for "IMPROVEMENTS IN THE CONSTRUCTION OF
SAFETY VALVES," to be as follows:-
In order to fully utilize the pressure of the escaping steam, which in
the ordinary construction of safety valves is almost entirely lost, we

page_text: provide a spindle above the valve proper for raising a weighted lever in
the usual manner. With this spindle or with the lever we connect a
plate or washer, herein-after called lifter, within the steam chamber sur-
mounting the boiler or generator to which the safety valve is fitted.
The steam, having come out of the valve opening at a certain pressure,
acts upon the lifter at a reduced pressure, and having thereby assisted in
raising the lifter or the weight itself, as the case may be, escapes
through the open space between the periphery of the lifter and the
chamber. By this means the pressure preserved by the steam after
passing through the valve opening is turned to useful account in such a
manner as to induce the rise of the valve to the full extent of its area,
thereby imparting greater efficiency to the valve, and permitting of the
reduction of its proportions. With a view to regulate the escape of the
steam after acting upon the lifter we provide an outlet pipe, the opening
of which may be adjusted by means of a cap, piston, or slide valve fitted
thereto, and furnished with a screwed spindle working within the side of
the outlet pipe, so that by turning this spindle the cap, piston, or slide
valve is placed in such a position as cither to close or open the outlet,
and thereby increase or reduce the pressure of the escaping steam.
By a modification in the arrangement described we apply our
Invention to those safety valves in which loaded spiral springs are used
instead of weighted levers or dead weights. To this end we enclose the
spring between an internal casing screwed upon the spindle of the safety
valve, and furnished with a flange at its bottom, and an external casing
having a flange for dead weights to rest upon. We so fit the external
casing as to be kept in its normal position by the action of the spring
itself while the spring works, and to be pressed down by the dead
weights upon the flange of the internal casing as soon as the spring,
being broken or otherwise injured, ceases to act. In order to dispense
with the internal casing a collar or washer may be fitted to the spindle
below the spring; and in lieu of the dead weights a weighted lever may
be connected with the external casing.
In those cases in which a system of dead weights is substituted for the
ordinary weighted lever in loading the valve we prefer so to proportion
the dead weights as to enable them to hold the place, and discharge

page_text: By a modification in the application of our Invention we substitute a¨
series of elliptical springs for the spiral spring or springs alluded to in
the foregoing. In doing so we arrange the elliptical springs by means
of superposition or juxtaposition in such a manner as to enable each of
them to act independently of the rest of the series, and to be either self-
acting, or to be loaded, by means of dead weights or weighted levers
in the same mode as in the spiral spring arrangement herein-before
described.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Peter Samson and William Parker in the Great
Seal Patent Office on the 18th June 1874.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, PETER
SAMSON, of 27, Belmont Hill, Lewisham, in the County of Kent,
Engineer, and WILLIAM PARKER, of Laburnum Villa, Rushey Green,
Catford, in the County of Kent, Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Nineteenth day of December, in the
year of our Lord One thousand cight hundred and seventy-three, in.
the thirty-seventh year of Her reign, did, for Herself, Her heirs and
successors, give and grant unto us, the said Peter Samson and William
Parker, Her special licence that we, the said Peter Samson and William
Parker, our executors, administrators, and assigns, or such others as
we, the said Peter Samson and William Parker, our executors, admi-
nistrators, and assigns, should at any time agree with and no others,
from time to time and at all times thereafter during the term therein
expressed, should and lawfully might make, use, exercise, and vend,
within the United Kingdom of Great Britain and Ireland, the Channel
Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN THE CON-
STRUCTION OF SAFETY VALVES," upon the condition (amongst others) that
we, the said Peter Samson and William Parker, our executors or admi-
nistrators, by an instrument in writing under or their, or one of
their hands and seals, should particularly describe and ascertain
the nature of the said Invention, and in what manner the same was to

page_text: be performed, and cause the same to be filed in the Great Seal Patent
Office within six calendar months next and immediately after the date
of the said Letters Patent.
NOW KNOW YE, that we, the said Peter Samson and William Parker,
do hereby declare the nature of our said Invention, and in what manner
the same is to be performed, to be particularly described and ascertained
in and by the following statement and accompanying Sheet of
Drawings:-
In order to utilize as completely as possible the pressure of the steam
escaping from a safety valve, which in the ordinary construction of these
valves is almost entirely lost, we furnish the steam boiler or generator
with an additional appliance in the following manner :-To the valve
proper we fit a spindle for raising a weighted lever or a set of dead
weights upon the plan hitherto pursued. With this spindle we connect
a plate or washer, herein-after called lifter, within the steam chamber,
surmounting or otherwise connected with the boiler or generator to
which the safety valve is fitted. The steam, issuing out of the valve
opening at a certain pressure, acts upon the lifter at a reduced pressure,
and having thereby assisted in raising the lifter or the dead weight itself,
as the case may be, escapes through the open space between the
peripheries of the lifter and its seating. By this means the pressure
preserved by the steam after passing through the valve opening is
turned to useful account in such a manner as to induce the rise of the
valve to the full extent of its area, thereby enhancing the efficiency of
the valve, and permitting of a corresponding reduction of its proportions.
With a view to regulate the escape of the steam after acting upon the
lifter we provide an outlet pipe, the opening of which may be adjusted
by means of a cap, piston, or slide valve fitted thereto, and fur-
nished with a screwed spindle working within the side or the top of the
outlet pipe, so that by turning this spindle the cap, piston, or slide valve
is placed in such a position as either to close or open the outlet, and
thereby increase or reduce the volume, and consequently the pressure of
the escaping steam.
In those cases in which a system of dead weights is substituted for
the ordinary weighted lever in loading the valve we either place the
lifting arrangement herein-before described below the dead weights, and

page_text: cause the spindle to pass through the axis of these, or so proportion the
dead weights as to enable themselves to hold the place and discharge
the functions of the lifter. We also furnish such dead weights with a
system of water buffers for preventing the valve from rising suddenly.
By a modification in the arrangement herein-before described we
apply our Invention to those safety valves in which loaded spiral springs
are substituted for the ordinary construction of weighted levers or dead
weights. To this end we enclose the spring between an internal casing
screwed upon, or otherwise fitted to the spindle of the safety valve, and
furnished with a flange at its bottom, and an external casing having a
flange for dead weights to rest upon. We so fit the external casing as to
cause it to be kept in its normal position by the spring itself while the
spring acts, or to be pressed down by the dead weights against the flange
of the internal casing as soon as the spring, being broken or having other-
wise lost its elasticity, loses its efficiency. In order to dispense with the
þinternal casing a collar or washer may be fitted to the spindle below the
spring; and in lieu of the dead weights a weighted lever may in some
instances be connected with the external casing.
By another modification in the application of our Invention we sub-
stitute a series of elliptical or hyperbolical springs for the spiral spring
or springs referred to in the foregoing. In doing so we arrange such
springs by means of superposition or juxtaposition in such a manner as
to enable each of them to act independently of the rest of the series, and
to be either self-acting or to be loaded by means of dead weights or
weighted levers in the same manner as in the spiral spring arrangement
herein-before described.
In the accompanying Sheet of Drawings we have shewn in Figure 1 a
longitudinal section of a safety valve furnished with a weighted lever,
and constructed according to our Invention.
Figures 2 and 3 are a longitudinal section and a sectional plan of a
safety valve loaded with dead weights, and furnished with the lifter.
arrangement, the water buffer and the outlet pipe combined together in
the manner herein-before described, Figure 3 being likewise a sectional
plan of the lower portion of the weighted lever arrangement shewn in a
sectional elevation in Figure 1. The same letters of reference denote
identical parts or organs in all these Figures.

page_text: A is the top or other part of the steam boiler or generator to which
the safety valve is fitted; B is the steam chamber beneath the casing C;
D is the spindle surmounted by the weighted lever E in Figure 1, and
by the dead weights F in Figure 2. With this spindle the lifter G is
connected in such a manner as to be acted upon by the steam issuing
out of the steam chamber B, and thence forward to raise the lever E, or
the dead weights F, as the case may be. This lifter is shewn in an
enlarged sectional elevation in Figure 4. It consists of an annular
plate or washer W connected by means of a set of arms a, a, with the
boss fixed directly or indirectly upon the spindle D, so that the
plate W of the lifter hangs within the annular opening J of the
seating W¹. The interior sides o, p, of the seating, as well as the
peripheries c, d, of the annular plate W, are parallel to the axis of the
spindle D, and the seating W₁ is furnished with two flanges l, m, forming
an annular space beneath the plate W of the lifter. The center part f
of the seating is joined by means of a set of arms or ribs u to the
exterior part thereof. In the dead weight arrangement, shewn in
Figure 2, the spindle D passes through the dead weights F, and these
rest in this instance upon the flange H pertaining to the spindle D. In
the top weight F¹, Figure 2, we provide an annular recess g, and intro-
duce therein the annular buffer L, shewn in a sectional plan in Figure 5.
The cavity in the weight F¹ being filled with water or other liquid the
buffer L has for its effect to prevent the valve from rising suddenly, as
herein-before pointed out. The same description of water buffers may
be applied to the weighted lever arrangement, shewn in Figure 1, as
well as to other kinds of safety valves. To the casing C the outlet
pipe M is attached, and the slide valve N working within the inter-
mediate pipe O by means of a screw and handle P, Q, is so arranged as
to allow of the escape of the exhaust steam being regulated.
In Figure 6 we have shewn a sectional view of a loaded spiral spring
constructed according to our Invention. In this instance the spindle D
acts in a manner analogous to Figure 2. To it is fitted the internal
flanged casing R bearing upon it the spiral spring S, which in its turn
is surrounded by an external casing. T, upon the flange of which the
dead weights F are placed. The outlet pipe M corresponds to the one
shewn in Figure 2, and to the spindle D is fitted the lifter arrangement
shewn in Figures 1 and 2.
A

page_text: Figure 7 is a longitudinal section of part of a safety valve constructed.
according to our Invention, shewing a modification in the arrangement
of the spiral spring S, which in this instance is not loaded by dead
weights, and in which the internal casing is dispensed with, and the
external casing T divided in two parts.
Figures 8 and 9 are a longitudinal section and a sectional plan of a
system of elliptical or hyperbolical springs, which may be substituted
for the spiral spring shewn in Figures 6 and 7. The springs S, S,
consist of rectangular steel plates bent in the manner shewn in Figure 8,
enclosed in the rectangular case C, and separated from each other by
the bars V passing through the box C; and fixed within its sides. The
spindle D passes through the center of the springs S, which rest upon
the flanges or shoulders J, J, wherewith the spindle is furnished.
Having now described the nature of our said Invention, and illustrated*
the same in the accompanying Sheet of Drawings, we wish it to be
understood that we do not claim the use of lifting arrangements
generally for utilizing the steam proceeding from safety valve openings,
neither do we claim the use of spiral springs for safety valves, both
having been known and applied heretofore; but what we claim is,-
First. The use or employment of a lifter acted upon by the steam
entering a steam chamber connected with a boiler or generator, sub-
stantially in the manner described and illustrated, more particularly
in Figure 4 of the accompanying Sheet of Drawings.
Secondly. The use or employment of the self-loading spring arrange-
ment herein-before described and illustrated in Figure 6 of the accom-
panying Sheet of Drawings.
Thirdly. The use or employment of the water buffer for insuring the
gradual rising of the valve, as described in the foregoing, and illustrated
in Figures 1 and 2 of the accompanying Sheet of Drawings.
Fourthly. The use or employment of a lateral slide valve for regu-
lating the pressure of the escaping steam, substantially as herein-before
described and illustrated in Figures 2 and 3 of the accompanying Sheet

page_text: Fifthly. The use or employment of elliptical or hyperbolical springs
in connection with, or apart from, the lifter arrangement described, as
illustrated in Figures 8 and 9 of the accompanying Sheet of Drawings.
In witness whereof, we, Peter Samson and William Parker, have
hereunto set our hands and seals, this Tenth day of June, One
thousand eight hundred and seventy-four.
Witness,
JOSEPH THEODORE DANN,
43, Cowley Road,
Brixton,
S.W.
(L.S.) PETER SAMSON.
(L.S.) WILLIAM PARKER.