Improvements in Slide-gate Valves.
Year: 1890

page_text: Date of Application, 9th Dec., 1890-Accepted, 7th Feb., 1891
COMPLETE SPECIFICATION.
[Communicated from abroad by THE ROSS VALVE COMPANY, of 1, Oakwood
Avenue, Troy, New York, United States of America.]
Improvements in Slide-gate Valves.
I, HENRY HARRIS LAKE, of the firm of Haseltine, Lake & Co., Patent Agents,
45, Southampton Buildings, in the County of Middlesex, do hereby declare the
nature of this invention and in what manner the same is to be performed, to be
particularly described and ascertained in and by the following statement :-
Figure 1 of the drawings is a central vertical section of my improved valve,
showing the gate-carrier in side elevation.
Figure 2 is a side elevation of the gate-carrier detached, and viewed in the
direction right angular to the line of view in Figure 1.
Figure 3 is a central vertical section of the carrier and gate-seating mechanism,
taken on the broken line 3-3 in Figure 1 showing one of the gates in rear
elevation.
Figures 4 and 5 are views similar to that shown in Figure 1 of modifications.
Figure 6 is a side elevation of the gate-carrier shown in Figure 4 detached with
one of the gates in position, and the other removed.
A is the valve case which is provided with a chamber A' in which the gates A²
are adapted to slide transversely across the water channel A' to and from their
respective seats A' surrounding the oppositely located channel-openings A³ in the
chamber-walls.
The gates are supported by a carrier B which may be moved across the water-
channel in any known manner, as by the screw-stem B¹ fitting a correspondingly
screw-threaded central aperture B² the carrier, and held in a longitudinally fixed
position by the collar B' fixed upon the stem and supported by the detachable screw-
threaded cap A and gland nut A'.
One end of the stem projects exteriorly of the valve-case and is provided with an
operating handle B*.
The gates are connected with the carrier by trunnion supports, the trunnions B'
being fixed upon the carrier and severally adapted to enter and loosely fit a socket B
one in the back of each gate.
When desired, the trunnions may be fixed to the gates, and the sockets located
in the carrier.
The carrier is also provided with two open chambers B' respectively located on
opposite sides of the central screw-threaded stem-aperture.
Each of the chambers is provided with a wedge-shaped end-wall having on
opposite sides the inclines B8 shown by solid lines in Figure 2 and by dotted lines
in Figure 1. The end-walls of the chambers which are located opposite the wedge-
shaped ends are each provided with a central aperture B' adapted to receive one
arm of the bifurcate plunger C.
Each arm of the plunger is provided with a wedge-shaped head C¹ similar in form
to the wedge-shaped end-walls of the chambers.
When the bifurcate-arms are in position in the aperture B' the wedge-shaped
heads rest within the chambers, one at the end of each chamber opposite the wedge-
shaped end-wall of that chamber.
To facilitate the insertion of the plunger arms and the wedge-shaped heads within
their respective chambers, I provide the outside wall of one of the chambers with
an opening C' connecting with the central opening B' and adapted to receive one of
the plunger-arm heads, and the inside wall of the other, which separates the chamber
from the central screw-threaded aperture, with a similar opening C³ adapted to
receive the head of the other plunger-arm.

page_text: The plunger arms and heads are inserted through such openings to the position
shown in Figures 1 and 3.
The carrier is then placed upon the back of one of the gates, with the trunnion
in the trunnion socket, thereby closing one of the open sides of each carrier-
chamber, and a nest of bearing-blocks, balls or rollers inserted in each chamber in
the position shown in Figures 1 and 3. I have shown four metallic balls D two
at each end of the chambers, and a metallic roller D¹ in the centre of each chamber,
in engagement with the four balls. After the balls and rollers are inserted in the
chambers, the other gate is placed on the carrier in the relative position shown in
Figure 1 and the gates and carrier inserted in the main chamber A¹ where the gates
are held upon their supporting trunnions, and in a position to retain the balls and
roller in their respective chambers by the chamber-walls of the valve-case. The
carrier and gates are moved from one end of the main chamber to the other, by
rotating the screw-stem in the usual manner, to open and close the channel, the
gates hanging upon their supporting trunnions.
In closing or seating the gates, the plunger C travels with the gate-carrier toward
the bottom of the main chamber until its lower end strikes the rib or flange A"
which arrests the progress of the plunger.
The further movement of the carrier forces the wedge-shaped plunger head
against the lower pair of balls, and the wedge-shaped carrier abutment against the
upper pair of balls, as will be apparent from an inspection of Figure 1.
The movement may be continued until each one of the balls in each chamber
bears upon one of the gates, the carrier abutment, the plunger head and central
rollers forcing the gates closely to their seats.
I am aware that a wedge-shaped carrier, and wedge-shaped plunger have hereto-
fore been employed in connection with wedge-shaped seating-blocks, to seat the
gates, but in such a form of construction the scating pressure was not evenly
distributed along the gate-seats whereby it frequently happened that one side or
edge of a gate might not be brought into engagement with its seat, the opposite
edge of the gate being first seated and resisting the entire seating-pressure.
Such a form of construction required accurate fitting of parts, and was not
adapted to accommodate itself to the change of form resulting from wear, or to
distribute the pressure equally over the whole seating surfaces of the gates. A
slight obstruction of one part of such surface might disturb the balance of the
seating blocks, and be able to resist the seating pressure, and render it impossible
to tightly close the gates.
I have ascertained that by interposing between the seating blocks which come in
contact with the oppositely located gates, a mobile block, bearing upon both of such
gates, with its freedom of movement, in a plane intersecting the contact blocks,
limited by such blocks only, I am able to communicate, through such mobile block,
a uniform pressure to both gates at the points of contact between the bearing-blocks
and their respective gates.
The balls Dare the seating-blocks and the roller D³ is the mobile block.
By means of these nests of five blocks one in each chamber, connected by the
bifurcated seating plunger, I am able to apply the seating pressure at four points
on the back of each gate, and to distribute the pressure equally between such
points.
Any variation or irregularity in the form of the various parts due to wear, or
the expansion and shrinkage in casting, is readily compensated for by the mobile
block which changes its position as required to distribute the pressure.
By applying the seating pressure at four points on the back of the gates, the
gates do not tip on their seats or wear unevenly, but tightly close the whole channel
opening.
To facilitate the equal distribution of the seating pressure between both nests
of blocks in the two carrier chambers I provide the lower end of the seating plunger
with a shank which is adapted to have a laterally yielding movement after it strikes
the bottom of the valve case.

page_text: As a preferred form of construction I have shown a wheel or roller F journalled
in the foot of the shank, to engage with the rib or flange AB on the interior of the
case bottom. If one edge of the gate should happen to be thicker than its opposite
edge, the movements of the plunger shank and mobile block will cause the pressure
to be evenly distributed to the four contact points of the blocks on the backs of the
gates.
When desired, one gate may be dispensed with, the channel opening, closed by
that gate being located elsewhere, and the chamber wall affording a resisting
medium or bearing for the nests of balls on that side opposite the single gate to be
seated. I prefer to employ bearing blocks with cylindrical or spherical surfaces,
as shown in Figure 1-as such form affords the least frictional resistance to their
movements in evenly balancing and distributing the seating pressure, but bearing
blocks with plane bearing surfaces, as shown in Figures 4, 5 and 6 may be employed.
The trunnion sockets are made a little larger than the trunnions, so that the move-
ments of the carrier may be continued for a short distance after the gates have
come into engagement with their seats, to increase the seating pressure without
sliding the gates across their seats after the pressure has become sufficient to injure
the seating surfaces by a slide movement, and when the gates are open or unseated
a slight independent movement of the carrier and trunnions backward in their
sockets relieves the gates of most of the seating pressure and permits them to be
slid from their seats without injury to the latter.
In Figures 4 and 6-I have shown the gate-carrier provided with a single
chamber and the bearing-blocks D-in the form of rollers which respectively extend
across the opposite edges of each gate.
The trunnions are supported by the cross-bars H.
The central mobile-block D' is made to correspond in length with the rollers and
provided with the plane beveled surfaces H-adapted to respectively engage with
the four rollers D.
The mobile block is also provided with a central aperture H adapted to permit
the carrier stem to pass loosely through the same as the carrier travels up the stem.
The aperture is made somewhat larger than the stem to afford the block freedom
of movement without coming in contact with the stem.
The bearing block abutment H on the carrier may be provided with a plane
horizontal surface to engage the bearing blocks or rolls instead of wedge-shaped as
shown in Figure 1. and the plunger heads H* may each have a similar surface to
engage the lower pair of rolls the beveled surfaces of the mobile block sufficing to
transmit the seating pressure through the rolls to the gates.
It is obvious that the rolls D & block D' of Figure 4 may be cut transversely as
indicated by the dotted lines H' in Figure 6 in which case the several sections
would form nests of bearing blocks similar to those shown in Figure 1.
In Figure 5. the bearing-blocks D are provided with beveled surfaces J adapted
to engage with the central mobile block D'.
The bearing blocks engage with a plane abutment on the carrier and a plane
head on a seating plunger as shown in Figures 4 and 6.
One pair only of the seating blocks engage with a gate the other pair engaging
with the valve case which affords a resisting medium to distribute the seating
pressure upon the back of the single gate.
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 as new and desire to secure by
Letters Patent is :-
First. In a slide-gate valve the combination with the inclosing case; a slide
gate; a gate carrier having a bearing-block-engaging abutment; and a carrier-
stem projecting exteriorly of the case of a seating plunger a nest of bearing-blocks
interposed between such gate and a resisting medium comprising two pairs of
bearing blocks one pair bearing upon the gate and the other pair upon the

page_text: resisting medium and a mobile block interposed between the pairs substantially as
described.
Second. In a slide-gate valve; the combination with the inclosing case; a slide
gate; a gate carrier having a bearing-block-engaging abutment; and a carrier
stem projecting exteriorly of the case; of a seating plunger provided with a
laterally yielding foot; a nest of bearing blocks interposed between such gate and
a resisting medium comprising two pairs of bearing blocks one pair bearing upon
the gate and the other pair on the resisting medium and a mobile block interposed
between the pairs substantially as described.
Dated this 9th day of December 1890.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, Agents for the Applicant.