IMPROVEMENTS IN CIRCULAR SLIDE OR SLUICE VALVES, AND IN PORTS AND CASES FOR THE GAND"
Year: 1882

page_text: LETTERS PATENT to Walter Charles Church, of No. 14, Trinity Square,
Brixton, in the County of Surrey, for an Invention of "IMPROVEMENTS IN
CIRCULAR SLIDE OR SLUICE VALVES, AND IN PORTS AND CASES FOR THE
GAND"
PROVISIONAL SPECIFICATION left by the said Walter Charles Church at
the Office of the Commissioners of Patents on the 31st January 1882.
WALTER CHARLES CHURCH of No. 14 Trinity Square Brixton in the County
of Surrey. "IMPROVEMENTS IN CIRCULAR SLIDE OR SLUICE VALVES AND IN
PORTS AND CASES FOR THE SAME."
In the Specifications to Letters Patent granted to me on the 21st February
1872 No. 563, on the 19th August 1872 No. 2469 and on the 21st January 1880
No. 266 I described slide or sluice valves of circular form so arranged that while
they travel to and fro governing inlet and outlet passages they may also turn
partly round and thus constantly bring fresh portions of the rubbing surfaces into
action on each other, thereby equalising wear and reducing friction. I also
described the use of a central projecting bearing surface to sustain a large portion
of the pressure on the back of the slide, and I described means of giving the
slide its partial turn at each to and fro stroke by the use of rollers bearing with a
wedging action between the edge of the slide and straight guiding surfaces at the
sides of the valve case.
My present Invention relates to improvements in slides of this kind and in the
formation and arrangement of the passages which they govern. The ports over
which the slide works being annular segments extending each over a considerable
arc, I make them with a central rib or with two or more ribs which sustain the
edge of the slide and prevent it from being depressed so as to catch the edges of
the ports in its motion over them. I make the central support for the slide spread
out from its base to a circular form at the top, and I hollow out its upper face in
eccentric form on each side providing two opposite ribs projecting inwards which
supporting the slide over a greater width ensure greater uniformity of wear.
bolt down this central support and by means of one or more tic bolts passing
through the central hole of the slide I bolt down the middle part of the cover of
the slide case. As the pressure within the case straining down its under side is by
means of the tension on the tie bolts met by the pressure on the cover straining it
outwards, the tendency of the pressure to deform the port face or the cylinder is
thus provided against. The loop or buckle by which the circular slide is embraced'
01
I

page_text: and moved to and fro is guided between lateral guides so that if there is any
tendency to strain it transversely, the slide rod is not subjected to such strain
which is taken on the guides. These guides also furnish extended surfaces for the
rollers of the buckle to roll on and prevent the slide from receiving any tilting
motion. The pins in the buckle on which the rollers are mounted are connected
at their outer ends by a spring guard which extends across the slide and bears on
its middle part, thereby preventing the slide from becoming displaced from its
proper bearing. The guard is made with a slotted hole to allow its travel while
the central tie bolt passes through the slotted hole, or when there are several such
tie bolts, there may be corresponding slotted holes in the guard, or the guard may
be arranged to pass between between the bolts. Instead of a guard attached to the
buckle a disc may be fitted on the central tie bolt, with a spring and adjusting nut
to give the desired pressure of the slide against the faces. The central tie bolt, or
one or other of the tie bolts when there are several may be drilled up with an oil
hole for lubricating the working surfaces.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Walter Charles Church in the Great Seal Patent Office on the
29th July 1882.
WALTER CHARLES CHURCH of No. 14 Trinity Square Brixton, in the County
of Surrey.
"IMPROVEMENTS IN CIRCULAR SLIDE OR SLUICE VALVES AND IN
PORTS AND CASES FOR THE SAME,"
In the Specifications to Letters Patent granted to ine on the 21st February
1872 No. 563, on the 19th August 1872 No. 2469 and on the 21st January 1880
No. 266 I described slide or sluice valves of circular form so arranged that while
they travel to and fro governing inlet and outlet passages they may also turn
partly round and thus constantly bring fresh portions of the rubbing surfaces into
action on cach other, thereby equalising wear and reducing friction. I also
described the use of a central projecting bearing surface to sustain a large portion
of the pressure on the back of the slide, and I described means of giving the slide
its partial turn at each to and fro stroke by the use of rollers bearing with a
wedging action between the edge of the slide and straight guiding surfaces at the
sides of the valve case.
My present Invention relates to improvements in slides of this kind and in the
formation and arrangement of the passages which they govern. The ports over
which the slide works being annular segments extending each over a considerablo
arc, I make them with a central rib or with two or more ribs which sustain the
edge of the slide and prevent it from being depressed so as to catch the edges of
the ports in its motion over them. I make the central support for the slide spread
out from its base to a circular form at the top, and I hollow out its upper face in
eccentric form on each side providing two opposite ribs projecting inwards which

page_text: supporting the slide over a greater width ensure greater uniformity of wear. I
bolt down this central support and by means of one or more tie bolts passing
through the central hole of the slide I bolt down the middle part of the cover of
the slide case.
As the pressure within the case straining down its underside is by
means of the tension on the tie bolts met by the pressure on the cover straining it
outwards, the tendency of the pressure to deform the port face or the cylinder is
thus provided against. The loop or buckle by which the circular slide is embraced
and moved to and fro is guided between lateral guides so that if there is any
tendency to strain it transversely, the slide rod is not subjected to such strain
which is taken on the guides. These guides also furnish extended surfaces for tho
rollers of the buckle to roll on and prevent the slide from receiving any tilting
motion. The pins in the buckle on which the rollers are mounted are connected
at their outer ends by a spring guard which extends across the slide and bears on
its middle part; thereby preventing the slide from becoming displaced from its
proper bearing. The guard is made with a slotted hole to allow its travel while
the central tie bolt passes through the slotted hole, or when there are several such
tie bolts, there may be corresponding slotted holes in the guard, or the guard may
be arranged to pass between the bolts. Instead of a guard attached to the buckle
a disc may be fitted on the central tie bolt, with a spring and adjusting nut to give
the desired pressure of the slide against the faces. The central tie bolt or one or
other of the tie bolts when there are several may be drilled up with an oil hole for
lubricating the working surfaces.
The accompanying Drawings represent constructions of slides of the kind above
referred to and of the slide cases ports and passages with my improvements applied
to them as I will now describe.
Fig. 1 is a longitudinal section of part of a cylinder with its slide and its case,
Fig. 2 is a transverso section, Fig. 3 is a plan of the slide case partly in section,
Fig. 4 is a plan of the cover of the slide case, Fig. 5 is a plan of the projecting
piece for supporting the middle of the slide, and Figs. 6 and 7 are longitudinal
and transverse sectious of this piece, Fig. 8 is a plan and Fig. 9 is a side view of
the circular slide with the ring of the slide rod embracing it, the reciprocating rod
causing the slide to move to and fro while the slide is free to turn within the ring
of the rod. In the ports A A over which the slide travels, and which are made of
somewhat crescent form as described in my former Patents, I introduce central
ribs aa which support the edges of the slide as they move over the ports and
prevent them from deflecting downwards so as to catch against the edges of the
ports. When the slide and ports are of considerable size I introduce in cach port
several such ribs as a a. I make the piece B which supports the middle of the
slide with a central almost elliptical hollow b b so that it presents faces projecting
upwards on which work corresponding faces projecting down from the interior
surface of the back of the slide. I make the hollow bb of such a form that there
are two central parts 6' 6' which present greater breadth of bearing for the slide
and ensure greater uniformity of wear. The supporting pioco B is bolted to the
metal of the cylinder, engaging under it the head of a strong bolt C which extends
up through the central hole in the back of the slide and through a hole in the
cover of the slide case on which is screwed the nut o. The bolt C is thus made to
act as a tie rod connecting the side of the cylinder with the cover of the slide
case, so that the downwards pressure within the slide case which tends to deform
the cylinder by pressing it inwards is counteracted by the upwards pressure
against the cover of the slide case. Instead of a single bolt C several such bolts
may be employed in this manner with advantage when the slide and its case are
of large size, or the tying of the cylinder to the slide cover may be effected by a
tubular connection as I will hereafter describe. At each side within the slide case
is formed a straight surface D along which run the rollers E E that are mounted
on the ring F of the slide rod, these rollers being arranged in such a position that
when the slide rod moves to and fro each of the rollers alternately tends to wedge
itself between the guide D and the circular edge of the slide, and by its rolling to

page_text: turn the slide partly round always in one direction as indicated by the arrow in
Fig. 8.
In the surfaces D I form grooves d into which enter the sides of
the ring F that are made for a portion of their length straight. The ring
being thus held within these grooves while it travels to and fro is prevented from
exerting any twisting action on the slide in case the external parts of the slide rod¦
should be subjected to torsive strain. I connect the pins of the rollers D D by a
spring guard G which presses on the middle part of the back of the slide keeping
it bearing steadily on the port face. This guard has in its middle a slotted hole g
to allow of its free travel to and fro while the bolt C passes through it. The
arrangement of the tie bolt and pressure spring may be modified as shewn in the
longitudinal section Fig. 10, the transverse section Fig. 11, and the plan Fig. 12
and side view Fig. 13 of the slide. In this construction the spring guard G is
dispensed with, and instead of it a disc G¹ is fitted on the bolt C, this disc being
pressed by a spring adjustable by a nut C¹. When this arrangement is adopted
the flat sides of the ring Fare guided on pieces d¹ d' attached at each side to the
interior of the slide case. It is always desirable to have the ports A. A as short as
possible so as to avoid waste of steam in filling them at each stroke. By the
application of my improvements I am enabled to secure this advantage by the use
of a large slide without involving the great friction and loss of power attending
considerable enlargement of slides as they are usually constructed. Fig. 14 is a
longitudinal section and Fig. 15 a transverse section shewing a slide sufficiently
enlarged to obtain straight passages A A to the cylinder these being the shortest
possible. Fig. 16 is a plan of the slide case shewing the ports and Fig. 17 is a
plan and Fig. 18 n sido view of the slide, Fig. 19 is a plan of the central
supporting picce B. In this case the middle supporting piece B is extended
upwards in tubular form B¹ and the cover of the slide case is bolted to it, the
tubular piece B' with its bolting acting as a tie between the cylinder and the cover
-of-the-slide-case. The spring-guard G is attached to the ring of the slide rod at
points in the line of the rod and is made with a hole g sufficiently elongated to
allow of the to and fro travel of the guard past the tubular tie B'. The cavity B
under the central piece B inay communicate by a hole b with the exhaust passage.
In all the Figures similar parts are marked by similar letters.
Having thus described the nature of my Invention and in what manner the
same is to be performed, I hereby declare that I make no general claim to the use
of circular slides made to rotate as they reciprocate, nor to the use of a projecting
bearing piece for supporting the back of such slides or of crescent shaped ports to
be governed by them, but I claim :
First. Introducing into the ports bearing pieces a to prevent depression of the
edge of the slide, substantially as described.
Second. Forming the bearing piece B with a nearly elliptical hollow with
lateral widened parts substantially as and for the purposes herein set forth.
Third. Connecting the cover of the slide case to the body of the cylinder by one
or more tie bolts or by a tubular tie substantially as and for the purposes herein
Bet forth.
Fourth. The use of an adjustable spring disc such as G¹ for pressing the slide
against the port face, substantially as described with reference to Figures 10, 11, 12
and 13.
In witness whereof I the said Walter Charles Church have hereunto set my
hand and seal this Twenty-eighth day of July in the year of our Lord