AN IMPROVED MODE OF AND APPARATUS FOR PREVENTING PRIMING IN STEAM BOILERS, AND PRO
Year: 1869

page_text: LETTERS PATENT to Robert Crickmer, of Doris Street, Lambeth, in
the County of Surrey, Engineer, for the Invention of "AN IMPROVED
MODE OF AND APPARATUS FOR PREVENTING PRIMING IN STEAM BOILERS, AND
PROVISIONAL SPECIFICATION left by the said Robert Crickmer at the
Office of the Commissioners of Patents, with his Petition, on the
1st October 1869.
I, ROBERT CRICKMER, of Doris Street, Lambeth, in the County of
Surrey, Engineer, do hereby declare the nature of the said Invention
for "AN IMPROVED MODE OF AND APPARATUS FOR PREVENTING PRIMING IN STEAM
BOILERS, AND FOR REGULATING THE SUPPLY OF STEAM THEREFROM," to be as
follows:-
My Invention relates to a method of and apparatus for preventing the
priming which is such a frequent and serious cause of inconvenience in
steam boilers, and also for automatically regulating the supply of steam
from a boiler in such a manner as to obtain the greatest useful effect
therefrom, more especially in the cylinders of locomotive engines.

page_text: The said Invention consists chiefly in so arranging the parts of the
apparatus that the area of the passage leading from the boiler to the
engine or apparatus where the steam is to be used is increased or
diminished automatically according to the pressure of steam in the
boiler, that is to say, when the pressure is low and the steam is being 5
generated slowly the area of the said passage is so reduced in size that
the steam can only be taken slowly from the boiler, but as the pressure
in the boiler increases and the evaporation becomes more rapid the area
of the passage is increased to a corresponding extent.
The said Invention also consists in the peculiar arrangement of valves ]
or pistons in combination with the passages leading from the boiler to
the engine or apparatus where the steam is to be used.
As an illustration of my said Invention I will describe one method of
carrying the same into practice. A cylinder is secured by any suitable
means upon the top or other convenient portion of the boiler, its lower
end opening into the steam space therein. At one side of the said
cylinder and in about the centre of the same lengthwise is a pipe or
tube also communicating with the boiler, and above the opening of this
pipe is another pipe or tube leading from the cylinder to the engine or
apparatus where the steam is to be used. The two pistons are attached :
to one rod or spindle and are so arranged that the lower one works
between the bottom of the cylinder and the aperture of the pipe which
leads therefrom to the boiler, while the upper piston works above the
said pipe, and when the pistons are in their lowest position the said
upper piston covers the aperture of the pipe leading to the engine. The
aperture of the pipe leading to the boiler is always open, so that the
space between the two pistons is always filled with steam, which passes
into the supply pipe slowly or rapidly as the aperture is more or less
uncovered by the rising of the piston. The spring which acts upon the
pistons in opposition to the steam pressure must be so regulated that the
uncovering of the aperture of the supply pipe will be in accordance with
the pressure and evaporation in the boiler. Any suitable spring or
springs may be employed for this purpose.
In some cases I may employ an ordinary spring balance such as is
commonly applied to the safety valves of locomotive and other engines..
I prefer, however, to use a peculiar adjustable spring arrangement
which I have designed especially for the purpose, and which is as
follows: To the upper end of the piston rod or spindle I connect

page_text: one end of a lever whose fulcrum is fixed at a short distance from
the said end upon a rod or bar extending below the said lever. Upon
this rod or bar I place a sliding piece, which is provided with a spiral or
other spring whose upper end is connected to the lever. By adjusting
this sliding piece and spring nearer to or farther from the fulcrum
the resistance of the spring to the steam pressure is diminished or
increased, and the apparatus may therefore be accurately adjusted to the
evaporation of the boiler.
The same apparatus may be advantageously applied with slight modi-
fications to a locomotive engine to regulate the supply of steam to the
cylinder, so that there shall not be a greater pressure of steam therein
than can be utilized for tractive force. In this case the valves or
pistons are so arranged that the area of the supply aperture is diminished
as the pressure in the boiler increases.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Robert Crickmer in the Great Seal Patent Office
on the 31st March 1870.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ROBERT
CRICKMER, of Doris Street, Lambeth, in the County of Surrey, Engineer,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the First day of October, in the year of
our Lord One thousand eight hundred and sixty-nine, in the thirty-third
year of Her reign, did, for Herself, Her heirs and successors, give and
grant unto me, the said Robert Crickmer, Her special licence that I,
the said Robert Crickmer, my executors, administrators, and assigns,
or such others as I, the said Robert Crickmer, my executors, adminis-
trators, 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 "AN IMPROVED MODE OF AND
APPARATUS FOR PREVENTING PRIMING IN STEAM BOILERS, AND FOR REGULATING THE
SUPPLY OF STEAM THEREFROM," upon the condition (amongst others) that I
the said Robert Crickmer, my executors or administrators, by an instru-

page_text: ment in writing under my, or their, or one of their hands and seals,
should particularly describe and ascertain the nature of the said Inven-
tion, and in what manner the same was to 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 I, the said Robert Crickmer, do hereby declare
the nature of my said Invention, and in what manner the same is to
be performed, to be particularly described and ascertained in and by the
following statement, reference being had to the accompanying Drawing
forming a part of this Specification :-
My Invention relates to a method of and apparatus for preventing the
priming which is such a frequent and serious cause of inconvenience in
steam boilers, and automatically regulating the supply of steam from
a boiler in such a manner as to obtain the greatest useful effect
therefrom.
The said Invention consists chiefly in so arranging the parts of the
apparatus that the area of the passage leading from the boiler to the
engine, or apparatus where the steam is to be used, is increased or
diminished automatically according to the pressure of steam in the
boiler, that is to say, when the pressure is low and the steam is being
generated slowly the area of the said passage is so reduced in size that
the steam can only be taken slowly from the boiler, but as the pressure
in the boiler increases and the evaporation becomes more rapid the area
of the passage is increased to a corresponding extent.
The said Invention also consists in the peculiar arrangement of valves
or pistons in combination with the passages leading from the boiler to
the engine or apparatus where the steam is to be used and with a
counteracting spring or weight.
In carrying the said Invention into practice a cylinder is secured by
any suitable means upon the top or other convenient portion of the
boiler, its lower end opening into the steam space therein. At one side
of the said cylinder and in about the centre of the same lengthwise is a
pipe or tube also communicating with the boiler, and above the opening
of this pipe is another pipe or tube leading from the cylinder to the
engine or apparatus where the steam is to be used. The two pistons are
attached to one rod or spindle and are so arranged that the lower one
works between the bottom of the cylinder and the aperture of the pipe
which leads therefrom to the boiler, while the upper piston works above

page_text: the said pipe, and when the pistons are in their lowest position the said
upper piston covers the aperture of the pipe leading to the engine.
The aperture of the pipe leading to the boiler is always open, so that
the space between the two pistons is always filled with steam, which
passes into the supply pipe slowly or rapidly according as the aperture is
uncovered by the rising of the piston. The spring which acts upon the
pistons in opposition to the steam pressure must be so regulated that
the uncovering of the aperture of the supply pipe will be in accordance
with the pressure and evaporation in the boiler. Any suitable spring
or springs may be employed for this purpose.
In some cases I may employ an ordinary spring balance such as is
commonly applied to the safety valves of locomotives and other engines.
I prefer, however, to use a peculiar adjustable spring arrangement
which I have designed especially for the purpose and which is as
follows:-To the upper end of the piston rod or spindle I connect one
end of a lever whose fulcrum is fixed at a short distance from the said
end
upon a rod or bar extending below the said lever. Upon this rod or
bar I place a sliding piece, which is provided with a spiral or other
spring whose upper end is in contact with the lever. By adjusting this
sliding piece and spring nearer to or farther from the fulcrum the
resistance of the spring to the steam pressure is diminished or increased,
and the apparatus may therefore be accurately adjusted to the evapora-
tion of the boiler.
The same apparatus may be advantageously adapted to a locomotive
engine to regulate the supply of steam to the cylinder with such modifi-
cations that while priming is prevented there shall not be greater
pressure of steam in the cylinder than can be utilized for tractive force.
In this case the valves or pistons are so arranged that by one of them
the area of the supply aperture is diminished when the pressure in the
boiler increases beyond what will produce a useful effect.
In order that my Invention may be fully understood, I have shown
in the accompanying Drawing various modifications of the apparatus
which I use in carrying the said Invention into practice, and I will now
proceed to describe the same.

page_text: boiler; Figure 2 is a similar section of the said apparatus shewing the
same provided with a flat resisting or counteracting spring instead of
the spiral or coiled spring shown in Figure 1; Figure 3 is an exterior
clevation illustrating a modification of the said apparatus in which the
pistons are arranged in connection with a throttle valve, as herein-after
described.
Figure 4 illustrates a modification of my apparatus in which the
steam passes from under the piston instead of between two pistons to the
outlet passage.
The cylinder a is securely attached by bolts or screws to the top of
the boiler or any other convenient portion thereof, which will allow the
lower end of the cylinder to open into the steam space A, or it may
be indirectly connected to the boiler by a tube or pipe arranged to
open into the steam space. In the apparatus shewn in Figure 1 it will
be seen that the cylinder a has another aperture or passage 6 communi-
cating with the steam space of the boiler and opening into the cylinder a
between the two pistons c, c'. The third aperture d communicates with
the engine cylinder or other vessel or apparatus where the steam is to be
used. It will be obvious from the arrangement of these passages that
there is a clear passage for the steam through the cylinder a between
the two pistons. The aperture 6 is always open; its area therefore is
not increased or diminished, but the area of the aperture d is increased
and diminished with the pressure in the boiler. It will be seen that this
aperture is so arranged in relation to the piston c that when there is no
pressure in the boiler the said piston, which forms a circular slide valve
nearly or entirely covers the said aperture, but as the latter rises in the
cylinder the said aperture is proportionately enlarged or uncovered. The
counter pressure or resistance which tends continually to depress the
piston against the pressure in the boiler is preferably obtained from a
spiral spring arranged, as shewn in Figures 1 and 4, in combination with
a lever e. The spring e¹ is enclosed within a box or case f, which is
fitted to slide endwise upon the rod or bar 9 and is provided with a
screw / or other means whereby when correctly adjusted it can be fixed
immovably upon the said bar. By this arrangement of the spring I can
adjust the same accurately to offer such resistance to the pressure of the
steam upon the piston c that the rising of the piston and the consequent
enlargement of the outlet aperture d will be exactly proportioned to the
pressure in the boiler. I do not, however, confine myself to the use of

page_text: a spiral spring, as I may use a flat spring e³, as shewn in Figure 2, and
in some cases may dispense altogether with a lever and apply a spiral
or other suitable spring directly to the piston.
In the modification of my apparatus illustrated in Figure 3 instead of
having the upper piston or valve arranged to increase or diminish the
area of the passage, I employ a throttle valve c³ which opens or closes
as the piston rises or descends in the cylinder a. The piston is provided
with a rod c³, which extends up beyond the top of the cylinder, where it
is jointed to one arm i of a lever which has its fulcrum in a bracket j
attached to the said cylinder. The other arm of this lever is pro-
vided with a pin which fits in the slot of the lever Z. The said lever
has its fulcrum in the bracket m formed on or attached to the cylinder a.
The short arm of this lover is connected by the link n to the arm c
of the throttle valve c³, and the arm of the said lever carries a weight
P, which in this instance is used as a substitute for a spring to counteract
the pressure of the steam upon the piston c. The throttle valve is so
arranged that it closes the pipe 6 when the piston c is in its lowest
position and opens the said pipe as the piston rises.
In Figure 4 I have shewn another modification of my said apparatus.
In this case it will be observed that I employ only one piston and
dispense with one of the apertures communicating with the boiler.
When no pressure exists in the boiler the piston c completely covers the
aperture d, but as the pressure increases and raises the piston the latter
uncovers the said aperture and the steam passes through the same
from below the piston c, instead of between the two pistons as in the
other arrangements of my apparatus herein described.
It is obvious that besides the modifications of my apparatus herein
described and shewn in the accompanying Drawing other forms of
valves and springs may be devised, which if not so advantageous in
some respects as those I have shewn and described may yet effect the
automatic opening and closing of the steam passages according to the
purpose of my Invention.
Having thus fully described the said Invention, and shewn how
the same may be conveniently and advantageously carried into practice,
I wish it understood that I claim,―
First. Preventing the priming of a steam boiler by automatically
regulating the area of the passage whereby the steam is taken from the

page_text: same, so that such area is increased and diminished in proportion to the
pressure in the boiler.
Second. The arrangement for the purpose aforesaid of the pistons or
valves in combination with the steam passages and apertures and with
a counteracting spring or weight in such a manner as to effect the
desired opening or closing of the steam passages, substantially as set
forth.
Third. Applying the counteracting spring to a lever and making the
samo adjustable upon a fixed bar or rod, substantially as and for the
purposes herein set forth.
set
In witness whereof, I, the said Robert Crickmer, have hereunto
my hand and seal, this Thirtieth day of March, in the year of
our Lord One thousand eight hundred and seventy.
Witness,
HARRY WRAIGHT.
ROBT. CRICKMER. (L.S.)