IMPROVE- MENTS IN SAFETY VALVES
Year: 1873

page_text: LETTERS PATENT to William Crees Taylor, of Liverpool, in the
County of Lancaster, Engineer, for the Invention of "IMPROVE-
MENTS IN SAFETY VALVES."
Sealed the 29th May 1874, and dated the 6th December 1873.
PROVISIONAL SPECIFICATION left by the said William Crees Taylor
at the Office of the Commissioners of Patents, with his Petition,
on the 6th December 1878.
I, WILLIAM CREES TAYLOR, of Liverpool, in the County of Lancaster,
Engineer, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN SAFETY VALVES," to be as follows:-
This Invention has for its object to provide means whereby safety
valves for steam boilers shall have greater motion when in action than
the resisting power, and also to obtain uniform resistance to the lift
For these purposes I
of the valve proper in spring safety valves.
employ a lever to act on the valve or its spindle, and apply the
resistance between the fulcrum and the valve. If the fulcrum is

page_text: between the valve and the resisting power the length of the lever from
the valve to the fulcrum is greater than from the fulcrum to the resisting
power.
In the construction which I prefer two valves are used, and resistance
to their rising is caused by the ends of one or more elliptical or so-called |
coach springs resting on the levers between each valve and fulcrum.
In the above arrangement as the resistance of the spring increases
whilst the valve is rising the point of resistance is brought nearer to the
fulcrum of each lever by the outward motion of each end of the spring
and consequent flattening.
To facilitate the said outward motion I interpose antifriction rollers
i
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said William Crees Taylor in the Great Seal Patent
Office on the 6th June 1874.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
OREES TAYLOR, of Liverpool, in the County of Lancaster, Engineer, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Sixth day of December, in the year
of our Lord One thousand eight hundred and seventy-three, in the
thirty-seventh year of Her reign, did, for Herself, Her heirs and suc- ¿
cessors, give and grant unto me, the said William Orees Taylor, Her
special licence that I, the said William Crees Taylor, my executors,
administrators, and assigns, or such others as I, the said William
Crees Taylor, 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

page_text: Britain and Ireland, the Channel Islands, and Isle of Man, an Invention
for “IMPROVEMENTS IN SAFETY VALVES," upon the condition (amongst others)
that I, the said William Crees Taylor, my executors or administrators, 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.
NOW KNOW YE, that I, the said William Crees Taylor, 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
Sheet of illustrative Drawings, and to the figures and letters marked
thereon, that is to say:-
This Invention has for its object to provide means whereby safety
valves for steam boilers shall have greater motion when in action an
the resisting power has, and also to obtain uniform resistance to the lift
of the valve proper in spring safety valves. For these purposes I employ
a lever to act on the valve or its spindle, and apply the resistance
between the fulcrum and the valve. If the fulcrum is between the
valve and the resisting power the length of the lever from the valve to
the fulcrum is greater than from the fulcrum to the resisting power.
In the construction which I prefer two valves are used, and resistance
to their rising is caused by the ends of one or more eliptical or so-called
coach springs resting on the levers between each valve and fulcrum.
In the above arrangement, as the resistance of the spring increases
whilst the valve is rising, the points of resistance are brought nearer to
the fulcrum of each lever by the outward motion of each end of the
spring and consequent flattening thereof.
To facilitate the said outward motion I interpose antifriction rollers
between the ends of the spring and the levers.
Knife edge bearings are used by preference, and easing and adjusting
goar provided.
gear provided
Spiral or other springs may be used,

page_text: DESCRIPTION OF THE DRAWINGS.
Figs. 1 and 2 are sectional views showing a simple form of safety valve
and accessories constructed under my Invention. Like letters denote
the same parts. a, valve; b, valve seating; c, lever resting on valve
spindle e and fulcrum studƒ; 9, weight or resisting power.
It will be obvious that the valve a has greater motion than the weight
or resisting power g.
A spring might be used instead of the weight.
Fig. 3 is a modification of valve and parts in which two levers o
resting on the fulcrum studs ƒ and the valve spindle e are used. An
elliptical spring & secured in the piece i acts as the resisting power. In
this modification considerable valve motion is secured with but small
spring compression. As the tension of the spring increases during the
rising of the valve, the points of action of the spring on the levers c
approach the fulcrum studs f, so as to give greater leverage to the valve:
and equalize the downward pressure during every part of the rise or
fall.
Fig. 4 is a sectional view, and Fig. 5, a plan view, part of the
cover being removed, showing a modification of the valve above
described under Fig. 8, fitted up for use on board ship; a, valves; two
valves are used; b, valve seatings forming part of valve case; c, cover
for valve case; e, levers, one for each valve resting on fulcrum studs f;
9, elliptical or coach spring supported at its centre by the piece h, its
ends i acting on the levers e through the friction rollers j; k, easing
gear.
The friction rollers ; are employed to ease friction due to the sliding
of the ends of the spring g on the levers e during rising and falling of
the valve. In this as in the foregoing example the pressure on the
valve is uniform; Z, escape pipe for steam; m, screw for increasing
pressure of spring on levers.
It will be obvious that the valves and appliances can be secured from
being tampered with by any ordinary locking apparatus. Moreover,
unlike safety valves as heretofore constructed, considerable tightening
of the spring would produce but little extra pressure if the tightening
mechanism were got at.
Figs. 6 and 7 are sectional views of modifications under my Invention,

page_text: in which spiral springs are used as the resisting power. In Fig. 6 the
springs act between the fulcra and the valve; in Fig. 7 the fulcra are
between the springs and the valve, but in both cases the valves have
greater motion than the springs; a, valve; b, levers; c, fulcra;
d, springs.
Fig. 8 is a sectional view of a modification of valve, in which an
elliptical spring is used, and in which the fulcra are between the points
of resistance and the valve. The distance from the fulcra to the valve
being greater than from the fulcra to the spring, the valve ends of the
levers have greater travel than the spring ends. The spring thus
receives but small amount of compression, although the valve travel is
considerable.
Having now described the nature of my said Invention, and par-
ticularized the same so that others will be enabled to carry it into
practice, I claim,—
First. Arranging lever safety valves in such manner that the resisting
power acts between the fulcra and the valve, substantially as described
and illustrated for the purposes set forth.
Second. Arranging safety valves and appliances so that the valve has
greater travel than has the resisting power, substantially as described
and illustrated for the purpose set forth.
Third. Using in combination the antifriction rollers j, spring g, and
levers e, substantially as described and illustrated for the purpose set
forth.
In witness whereof, I, the said William Crees Taylor, have here-
unto set my hand and seal, the Fourth day of June in the year
of our Lord One thousand eight hundred and seventy-four.
In the presence of
JAMES JOHNSON,
Patent Office,
Clayton Square,
Liverpool.
W. C. TAYLOR. (L.S.)