IMPROVE- MENTS IN THE CONSTRUCTION OF STOP VALVES.
Year: 1883

page_text: PROVISIONAL SPECIFICATION left by the said James Tate at the Office
of the Commissioners of Patents on the 21st September 1883.
JAMES TATE of Bradford in the County of York, Foreman Mechanic. IMPROVE-
MENTS IN THE CONSTRUCTION OF STOP VALVES.
The object of my invention is to construct stop valves of steam engines in such
a manner, that the same can be automatically closed; the apparatus being so
arranged as to act direct upon the valve seating cover; and consists in securing to
the valve casing, a cylinder in which is fitted a piston that is connected to the
cover of the valve seating by a spindle.
The cylinder piston when the valve is open has the pressure of steam on both.
sides of it, and when a tap in connection with the underside of the piston is
operated upon by means of electricity, or by a cord as the case may be, an armature
is raised which liberates a weight, opening the tap, and allowing the pressure to
escape from the underside of the piston, that on the other side moving the piston
and thereby closing the valve.
C

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said James Tate in the Patent Office on the 21st March 1884.
JAMES TATE of Bradford in the County of York, Foreman Mechanic IMPROVE-
MENTS IN THE CONSTRUCTION OF STOP VALVES
The object of my invention is to construct stop valves of steam engines in such
a manner that the same can be automatically closed, the apparatus being so
arranged as to act direct upon the valve seating cover: and consists in securing to
the valve casing a cylinder in which is fitted a piston that is connected to the
cover of the valve seating by a spindle. The cylinder piston when the valve is
open has the pressure of steam on both sides of it, and when the magnet is operated
upon by electricity or the catch weight liberated by a cord, as the case may be in
the manner hereinafter described, the pressure of steam on one side of the piston
is relieved, the pressure on the other side closing the valve.
In order that my invention may be better understood I bave appended drawings
illustrative thereof and marked the same with letters of reference.
In the accompanying drawings. Figure 1 represents an elevation of a stop valve
-fitted up according to my invention. Figure 2 is a vertical section through the
centre of the same, except the valve spindle and piston block. The apparatus
illustrated by these Figures shew the arrangement for closing the valve when the
pressure is flowing from the underside of the seating in the direction indicated by
the arrow.
To the top flange of the stop valve casing A, I secure the cylinder B which has
the flange D recessed in the bottom flange of the cylinder so as to form a blank
end to the latter: the cylinder is fitted with a piston block E which is secured on
the valve spindle F, the spindle being connected to the valve seating cover V and
continued in the opposite direction through the hollow screw G. Around the
screw G inside the casing K is a collar having a feather key secured thereto which
fits into a groove cut longitudinally through the threads of the hollow screw G:
and to the collar is also secured one end of a coiled spring J the other end of which
is attached to the casing K.
In order to open the valve, the nut L is run down the thread on valve spindle F
against the boss of hand wheel G¹, the latter is then turned, the hollow screw G
raising the valve cover V from off the valve seating, and coiling up the spring J
which is of similar construction to springs used in the chain barrels of watches.
When the valve has been opened in the manner described, the nut L is run back
to the position shewn on drawing, and the pressure of steam admitted on to both
sides of the piston block E, to the top side through the passage or opening C¹ and
to the bottom side of the piston through the clearance space around the valve
spindle F, the piston is thus is an equilibrium of pressure, and the piston and
valve seating cover V are retained in the position by the friction of the metallic
packing M against the valve spindle F.
The electro magnet N may be fixed in any convenient position, and wires
connected thereto extending to any place or places in the works, and when it is
desired to close the valve, the electric circuit is completed by any well known
method which causes the magnet N to attract the armature P to the said magnet,
thereby liberating the catch weight R which will fall, in the direction of the
curved arrow, the boss R' at the back thereof shewn by Fig 3 coming in
contact with catch spring S moving it clear of the catch arm S¹ which is secured
to the spindle S* that is connected to the plug spindle of tap T as shewn by Fig. 4.
When the catch arm §¹ is liberated the coiled spring O shewn in Figure 5 which is
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page_text: attached to the spindle S' and casing will uncoil, and cause the tap T to be opened
thus allowing the pressure of steam from the underside of piston E to escape
through pipe U to the engine condenser or atmosphere, the pressure on the opposite
side of the piston being maintained through the opening C¹ overcomes the friction
of the metallic packing M, and forces the piston E towards the valve seating, the
hollow screw G being thus relieved, the spring J uncoils, causing the feathered key
in the collar to rotate the hollow screw G which slides through the collar and
follows up the spindle F finally closing the valve.
Or in place of the magnet N a cord may be secured to the armature P, as at P¹
and conducted to some distant place, which when pulled raises the armature P,
thereby liberating the catch weight R which acts upon the plug of tap T in the
manner as before described.
When the steam pressure in the pipes is on the top side of the valve seating
cover V flowing through the opening O, the apparatus is constructed as shewn by
Fig 6 without the coiled spring J, the cylinder B, piston E, and spindle F are
constructed and attached to the valve seating cover V in the manner as before
described, as are also the armature P and connections to the underside of piston.
The valve when constructed as shewn by Figure 6 is opened in the manner as
before described, and when it is desired to close the same, the electric circuit is
completed or the cord pulled to raise the armature P, thereby liberating the catch
weight R which releases the pressure on the underside of the piston E as before
mentioned, the steam pressure on the other side actuating the piston until the
valve seating cover V is tight upon the seating.
By constructing valves in the manner described, and when used for supplying
engines with steam, the valve can be closed and the engine stopped from any part
of the works to which the wires or cord is conducted: and in the case when wires
and magnet N are used, should the engine be running above or below the regulated
speed, it can be stopped by arranging the circuit wires, that when the connecting
lever or traversing collar on the governor comes in contact with the wires or
metallic attachments connected thereto, the électric circuit is thereby completed,
thus causing the catch weight R to fall and the valve to close in the manner as
before described.
Having now described the nature of my invention, together with the manner in
which the same is to be or may be performed I wish it to be understood that what
I claim as my invention is:-
The combination of a stop valve with a pressure cylinder B fitted with piston E,
the spindle F of which acts direct upon the valve cover V when the pressure is
released from the underside of the piston by the tap T actuated by the electro-
magnet or cord in the manner and for the purpose as hereinbefore described.
In Witness whereof, I the said James Tate have hereunto set my hand and
seal this twenty-fourth day of December in the year of our Lord One Thousand
eight hundred and eighty-three
ΤΑ ΑΠΟ