IMPROVEMENTS IN. SAFETY OR OTHER VALVES AND MEA
Year: 1857

page_text: LETTERS PATENT to John Poole, "of-Number 2) Riley Street, Chelsea, in
the County of Middlesex, Engineer, for the Invention of "IMPROVEMENTS
IN. SAFETY OR OTHER VALVES AND MEA
Sealed the 11th August 1857, and dated the 11th February 1857.
PROVISIONAL SPECIFICATION left by the said John Poole at the Office
of the Commissioners of.Patents, with his Petition, on the 11th February
1857.
I, JOHN POOLE, of Number 2, Riley Street, Chelsea, in the County of
Middlesex, Engineer, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN SAFETY OR OTHER VALVES, AND IN MECHANICAL APPLIANCES
THERETO," to be as follows:-
In lieu of the present form of straight lever or bar, commonly called tho
"steelyard balance," as applied to safety valves of steam engine boilers and
other vessels, and which moves on hinges on one end, and presses on the valves
at an arranged distance along the bar or lever measured from the said hinge,
and which point resting on the valve is the outer end of a radius struck from
the said hingo or joint, and which radial point recedes as the bar or lever riscs,
thereby forceing, pulling, or causing the valve to loose its necessary vertical or
straight position, path, or action, and which causes it to jam or stick, first, I..
make or construct my valves with an oblong or rectangular slot.or opening on
the upper side, and terminating with a central guide pin moving through a
hole in the upper part of a frame or bracket, the lower end of which bracket is
affixed to the valve face or seat, or any other convenient place, and standing..

page_text: over the valve in the shape of a bow or arch, and in the said slot or opening I
place or work a lever or bar, with a cross at one end, resembling in shape the
letter T, with a pin passing through a slot or opening, and through the bar or
lever at a point of intersection of lines drawn through the centre of the long
arm and short one, and crossing each other at right angles, and on which the
said bar or lever hangs or hinges; and from each end of the short arms of
the lever, and connected thereto, is a paralell or radius rod with a moveable
joint, and which said radius rods, with moveable joints at the other end, are also
attached one on each side of the bracket bow frame, or arch, before mentioned,
the object and use of the said rods being to cause the valve to always have
and maintain a free vertical or straight path action or lift, and prevent it in
any way from sticking or jaming, or being pulled, drawn, or forced out of its
straight or proper path or course by the action of the said lever or bar.
Secondly, I further purpose using another straight bar or lever with a pin
passing through its centre, and likewise through the said slot or opening, in
any convenient part above or below the other bar or lever, and to which will
be attached two other paralall or radius bars or rods the same as before
described, and which I introduce for the purpose of maintaining the valve
in a straight line without the aid or use of the central guide pin, before
mentioned.
SPECIFICATION.in. pursuance of the conditions of the Letters Patent, filed
by the said John Poole in the Great Seal Patent Office on the
11th August 1857.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
POOLE, of 2, Riley Street, Chelsen, in the County of Middlesex, Engineer,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters-
Patent, bearing date the Eleventh day of February, in the year of our Lord
One thousand eight hundred and fifty-seven, in the twenty-first year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said John Poole, Her special licence that I, the said John Poole, my
executors, administrators, and assigns, or such others as I, the said John
Poole, my executors, administrators, 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

page_text: Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN SAFETY
OR OTHER VALVES, AND IN MECHANICAL APPLIANCES THERETO," upon the condition
(amongst others) that I, the said John Poole, my executors or adminis-
trators, by an instrument in writing under my, 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 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.
1. NOW KNOW YE, that I, the said John Poole, do hereby declare the
nature of my said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement, that is to say :-
a
The main object of my Invention is to construct my valve so that while
having the smallest amount of surface contact with the face or seat, it shall
also by means of certain appliances have its motion, when acted upon by the
steam or otherwise, in a vertical line or path upwards and downwards, and
hence avoid that defect of construction which in all other valves causes tliem
from the action of the lateral force to jam or stick in their seats, indicating
much less vertical pressure than is in reality acting against their under surface,
and proving the source of most dangerous explosions. I effect these as
follows: First, I construct the valve itself of a conical, cylindrical, circular
disc, or any of the now well-known forms. If, however, it be a surface or face
valve, in order to reduce the surface of contact to the smallest possible amount;
I propose to line or inlay a portion of the surface of the valve face, that is, the
surface on which the valve rests, with any soft metal or metallic alloy, and to
form the under surface of the valve itself so that a narrow ring or edge shall
project and indent into the said portion of soft metal on the other facc;
otherwise I reverse the arrangement, and inlaying the under side of the valve
with the soft metal or metallic alloy, I form a corresponding projecting ring or
ledge on the surface of the valve seat or face, so that when the valve rests upon
its face this ring or ledge shall indent into the soft metal, keeping it steam-
tight. I find that in practise the ring or ledge, whether in the under surface
of the valve or on the valve seat or. face, may be reduced to a very narrow
edge and yet remain perfectly steam-tight. When the valve is conical in
form I prefer to make the seat into which it fits of a cylindrical form, the
diameter being less than that of the greatest diameter of the valve, and having
the edge or lip at the mouth slightly rounded off, the effect of this arrange-
ment being to give the smallest possible amount of surface contact between

page_text: the valve and the seat, and at the same time to cause: the steam when
escaping to rise vertically upwards...
:
Second, with regard to the mechanical appliances for the purpose of causing
the valve when acted upon by the steam or otherwise to rise and fall in a direct
vertical line or path, so as to avoid the lateral pressure, and prevent it jamming
or sticking in its seat, for that purpose I propose to use any of the well-known
arrangements of parallel motion, or other combinations for obviating the effects
of lateral pressure, and causing a rod to move in a straight line. The
particular arrangement for that purpose which I prefer, but to which I by no
means confine myself, is as follows:-The spindle of the valve has its lower
end slotted out, or it may be of a forked or gimbal form, the forked end being
attached to the valve. Within the slot, and attached to it by a pin, vibrates a
small bar or link, the extremities of which are each attached to and turn freely.
on a radious rod; one end of each of these radious rods is, (on opposite sides
of the vibrating link) attached to and moves freely in a joint on a bracket or
frame, which said bracket or frame is fixed. to the valve seat or any other.
convenient place. The other extremity of each radious rod may either.
terminate in the end of the vibrating link, or they may be one or both
elongated in opposite directions, and serve for the balance levers of the valve..
If both terminate at the extremity of the vibrating link, then a balance lever.
may be attached to the said link for the purpose of regulating the pressure on
the valve, or the weight may be attached to the under face of the valve and
hang.suspended in the boiler, or in any other way so as not to interfere with
the action of the arrangement for producing the vertical motion of the valve
and spindle. The upper end of the spindle, which is formed in the shape of a
guide pin, passes through an eye or guide hole, provided for it in a bow, or arm,.
or connecting bar, binding the frame or bracket, before mentioned: Instead,
however, of the guide hole, a similar arrangement of the link and radious rods
may be attached to the upper part of the spindle. I do not prefer this,
however, as it tends to render the arrangement more complicated and
expensive.
I
In order to illustrate the above description the accompanying Drawings are
appended to this Specification. It is not intended, however, that these shall
exhibit all the methods by which the principle, of a "direct vertical. motion of
the valve" can be produced, which principle I particularly, claim as my. Inven
tion, but only the details, of one method of construction and arrangement
which I prefer, the dimensions, form, and mode of obtaining the vertical
motion of the valve requiring to be modified, varied, and altered for. each
different case..

page_text: DESCRIPTION OF THE DRAWINGS.
Figures 1, 2, and 3 are an elevation, section, and plan of the valve when
complete, the same letters indicating the corresponding parts in each. a is
the valve, attached to the spindle b, which is shewn slotted out in Figure 2, and
having suspended within it the vibrating link c, turning on the pin d, which
passes through through the sides of the spindle; e and f are the radious rods,
turning on the pins 9 and g¹ at the extremities of the vibrating link, and
radiating round the centres h and h¹ on the pins h, h', which are attached to
the frame k, k. The lower radious bar is elongated to form the balance
lever, the upper portion of the spindle forming the guido which passes
through the eye n in the bow springing from and connecting the upper part of
the frame. The valve a in Figures 1 and 2 is shewn, having its under surfaco
cut away so as to form a sharp arris round the edge, which embeds itself into
the ring of soft metal or metallic alloy o, o, in the face m.
Figure 4 shews the ring of soft metal or metallic alloy cast or imbedded
into the valve a, while the face m has got the edge at its lip projecting so as
to imbed in the soft metal o.
Figure 5 shews the form which I adopt for my valve seat when the valve is
connical, the seat m being cylindrical, but having its lip rounded off at a, a.
Having now particularly described my Invention, and how the same is to be
performed, I wish it understood that what I claim as new, and wish secured
by the said Letters Patent, are,-
First, diminishing the surface of contact between the valve and its seat or face.
Second, inlaying or imbedding the under surface of the valve or the upper
surface of the face with a ring of soft metal or metallic alloy, so that the
diminished edge may indent therein.
Third, any of the present known forms of parallel motion or other arrangements
for causing the valve to move vertically upwards and downwards when in action.
In witness whereof, I, the said John Poole, have hereunto set my hand
and seal, this Eleventh day of August, in the year of our Lord Ono
thousand eight hundred and fifty-seven.
Witness, JAMES WRIGHT,
10, Alfred Place,
Newington Causeway, London.
JOHN POOLE.
(L.S.)