Improvements in or relating to Automatic Relief Valves for Steam Engine Cylinders and Boilers.
Year: 1892

page_text: Date of Application, 26th July, 1892-Accepted, 3rd Sept., 1892
COMPLETE SPECIFICATION.
Improvements in or relating to Automatic Relief Valves for Steam
Engine Cylinders and Boilers.
A communication by FRANK SCHREIDT, of Mansfield, in the County of Richland
and State of Ohio, United States of America, Machinist.
I, WILLIAM PHILLIPS THOMPSON, F.C.S., M.1.M.E. of the Agency for Foreign
Patent Solicitors, 6 Lord Street, Liverpool and 6 Bank Street, Manchester, both
in the County of Lancaster and 323 High Holborn, in the County of Middlesex,
Civil Engineer, do hereby declare the nature of this invention and in what manner
the same is to be perforined, to be particularly described and ascertained in and
by the following statement :--
The objects of the invention are to provide means to prevent steam from coming
in contact with the spring, to provide means to adjust the springs to any desired
pressure, to provide an index to indicate the pressure upon the valve, and lock
them after adjustment, so that the valves may be removed for overhauling and
when replaced the adjustment will not be changed, to provide means to quickly
relieve the cylinder without affecting the relief valve, and for the attachment of
an indicator in direct communication with the live steam in the cylinder, to provide
means to temporarily move the relief valve, and testing it to be sure that it does
not stick to its seat or its action is not impeded from any cause, and finally to
so form the parts that they may be readily combined in a strong effective device
that requires little attention and is not liable to get out of order.
The invention will be first fully described in connection with the accompanying
drawings, in which like parts are indicated by similar reference letters wherever
they occur throughout the various views, after which it will be particularly referred
to and pointed out in the claims.
Referring to the drawings:
Figure 1 is a vertical diametrical sectional view of the improved valve arranged
to be applied to a horizontal engine.
Figure 2 is a modified form adapted to be applied to a vertical engine.
Figure 3 is a plan view of the cap and case taken through lines - of Figures 1
and 2.
Figures 4 and 5 are respectively front and edge elevations of the wrench for
temporarily actuating the valve by hand.
Figure 6 is a transverse sectional view of the auxiliary hand relief valve shown
in Figure 2 upon an enlarged scale.
Referring first to the form shown in Figure 1: The outer case is composed of
the two parts A A¹ united together by screw threaded connection at a.
The hollow globular part A of the valve case has a flanged branch a¹ to connect
with the cylinder, and a similar branch a², to connect with the waste drain or the
bilge pipe.
The valve B which is provided with wings 6, which fit loosely within branch a',
as well as the valve seat a³, are preferably formed of nickel or some non-corrosive
metal, the seat being for economy made in form of a ring and screwed into the
casing A.
The valve B is screwed onto the lower end of a tube C, which is fitted to slide
freely in the upper casing or shell A¹. Within the tube C is a follower D
centrally perforated and having a tubular stem d, extending through the cap c of
the tube C and packing nut c¹ and fitted so as to slide freely on the stem. The
upper edge of the tubular extension d has a V-shaped groove into which fits
correspondingly shaped edge of tube D' the latter having an exterior screw threaded
portion to engage a thread tapped in the neck a' of the case portion A¹, The

page_text: V-shaped joint is ground to make it close fitting so as to prevent water or steam
from coming in contact with the spring. The follower D is forced downwardly
within the tube C, by screwing down the tubular piece D'. A spiral spring E, is
compressed between the follower D and the valve B, within the tube C.
stem of the valve B extends through the coils of the spring E, tubular
extensions d, and tube D', and is fitted on its upper end with a cap nut 62.
The
On the upper end of the valve casing. A¹, is a circular flange, a', which is
provided with a series of perforations a, and laterally extending from the tube D'
is a lug which is countersunk upon the top and perforated to receive a screw
pin the lowering tapering end of which is adapted to enter any one of the
perforations in the flange a, and lock the tube D', and case A' together. The
purpose of this arrangement is, to regulate the tension of the spring E, and lock
the parts together so that the tension of the spring will always remain the same.
The top of the disc, or flange a³ is indexed opposite the perforations a, to indicate
what hole the pin d should be placed in, in order to give any desired tension to
the spring so as to hold the valve B to its scat with requisite pressure.
In order
to secure this result, after the valve has once been pressed to its seat with its
lightest pressure the pin is retracted by a suitable key and the pin turned with
the tube D' until the pin is brought successively into each one of the holes a, the
pressure necessary to force the valve from its sent is tested while the pin is in cach
one of the holes, and the pressure stamped upon the disc a. opposite the holes, so
that the engineer may readily adjust the valve to any pressure desired, by rotating
the tube D³, until the pin d² comes opposite the holes in the index marked with the
requisite pressure, for instance; for high pressure cylinder valves, the pin placed
in the hole marked 180, for low pressure valves it is placed in the hole marked 40
and for intermediate pressure valves in the hole marked 80, which means
respectively 180 lbs. pressure, 80 lbs. pressure, and 40 lbs. pressure.
Now it will be seen that the spring which regulates the valve and holds it to its
seat is entirely encased from contact with the steam and that once the pressure is
regulated after the casings A. A' are secured together, the valve with the upper
part of the casing A¹ may be removed for overhauling and when replaced the
tension of the spring will not be disturbed nor the pressure of the valve to its seat
varied.
It frequently happens that it is necessary to relieve or free the cylinder from
water, even when the pressure within the cylinder is insufficient to lift the valve B
from its seat, a forked lever H is therefore provided, shown in Figures 4 and 5.
The fulcrum of the lever is placed upon the flange a with the forks h', under
the cap nut, by pressing down the lever H, the stem is elevated carrying with
it the valve B, thus providing temporary relief for the cylinder, and for testing the
valve to see that it does not stick from deposits of the scale that may accumulate
from the water.
In the form shown in Figure 2, the valve case A, A', spring casing C, and the
spring pressed main valve B, are substantially the same as shown in the preceding
figure, excepting that the valve B' is integral with the spring casing C, being a
downward extension of it; from the inside of the spring casing bottom is an
upwardly extending nipple c', which is screw threaded to receive the packing
nut c², between which and the plunger D, the spring E is compressed to hold the
valve to its seat, the lower extension of the casing C, is chambered at c³ and
transversely perforated to communicate with the branch a of the outer casing A.
The lower part of the spring casing and valve B1 is centrally perforated to receive
the stem, and the screw threaded portion of the valve 6, which is an upwardly
closing valve having its seat 65 in the body of the valve B. The screw threaded
portion of the valve is cut away or longitudinally grooved 6, as clearly shown
in enlarged transverse section Figure 6. The upper end of the stem /³, is fitted
with a hand wheel B, by which the valve is lowered to afford temporary relief
through the branch a and brought back to its seat to lock the temporary relief
valve, and the valve B', as one piece.

page_text: The lower end of the valve case A, has a screw threaded branch to secure the
valve case in a T coupling F, which communicates with the cylinder; the coupling
has a horizontal branch, in which is secured a hand valve G, which is of the
ordinary construction, by which the cylinder may be quickly relieved if desired.
This valve is also intended to open communication direct with the live steam in
the cylinder and an indicator which may be attached at any time to the branch g,
thus avoiding the necessity of attaching a globe valve to the cylinder for indicating
purposes.
It is obvious to those skilled in the art to which this invention relates that many
mere mechanical changes may be made without departing from the spirit or scope
of the invention, and hence it is to be understood that the invention is not limited
to the precise details shown and described.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, as communicated to me by
my foreign correspondent, I declare that what I claim is :-
1. The combination of the valve case, a spring pressed relief valve within said
case, a housing for the valve spring rigidly secured to and movable with the valve,
and means such as shown for adjusting the tension of the spring and locking the
tension when adjusted substantially as shown and described.
2. The combination of the outer case, the valve, and the valve spring housing,
connected together and fitted to slide within said case, the follower D within
housing and having a stem extending to the outside, the tube D', screw threaded
through the case and forming part of the plunger stem, whereby the follower is
moved within the spring housing, the spring compressed between the follower and
the valve and means to lock the adjustment of the spring for the purpose of holding
it to the desired tension substantially as shown and described.
3. The combination of the two part outer case A A', the spring housing C and
attached valve B, fitted to slide therein, the follower D, having divided hollow
stem d D', the part D' being screw threaded through the neck of the part A', and
having laterally extending lug d, the screw pin d tapped into said lug and adapted
to interlock with the case and stem extending to the outside of the case and
provided with cap nut, substantially as shown and described.
4. The combination of the valve case, a spring pressed relief valve within said
case, a housing for the spring and follower provided with a screw threaded stem,
to compress or relax the spring, a supplemental valve as b, forming part of the
spring pressed valve but movable independent of it, the stem 63, and hand wheel B
to move said supplemental valve independent of the main valve, substantially as
and for the purpose set forth.
5. The combination of the outer case, the spring pressed relief valve therein,
means for adjusting the spring and locking the tension when adjusted and a
graduated index to indicate the pressure with which the relief valve is held to its
seat, substantially as shown and described.
6. The combination of the valve case, a spring pressed relief valve within it, and
an auxiliary relief and indicator valve as G, adapted to connect directly with the
cylinder, and having a screw threaded exhaust branch as g, for attaching an
indicator, said auxiliary valve being arranged to act independently of the spring
pressed relief valve, substantially as shown and described.
Dated this 25th day of July 1892
WM. P. THOMPSON & Co.,
Agents for the Applicant.