Year: 1890

page_text: of the steam-chest, and this surrounding space is established by means of corner
apertures i, that are formed in the top of the outer valve-section, the flange g being
within the line of the said corner apertures.
The outer valve-section flanges e (which as before stated, overlap the lower flange f
of the inner valve section A) serve as guides for the inner-valve-section, the inner
faces of said flanges e abutting closely against the outer faces of the end walls of
the said inner valve-section, and as the flanges ƒ do not extend to the inner faces of
the flange d it follows that a free communication is established about the flange f. A
yoke 15 is fitted upon the outer valve-section, and to this yoke there is connected a
valve-stem 16.
When the valve 11 is in the position in which it is shown in Fig. 3, it is at or near
the end of its right hand stroke, and the motive agent is passing from the steam-chest
through the open port a into the left hand end of the cylinder, the piston at this time
moving towards the right. When it is desired to cut off, the valve-stem is thrown
toward the left, so that the forward end of the valve will pass over the port a and cut
it off from communication with the steam chest. During this motion of the outer
valve section B the inner valve section A remains stationary, and the motive agent in
the right hand end of the piston is free to exhaust through the entirely open port b
the interior of the valve section A, and the exhaust-port c.
Almost immediately after the entrance to the port a is closed the right hand end of
the valve-section B will come in contact with the valve section A, as shown in Fig. 4
and any continued onward movement of the valve-stem 16 will carry the valve 11 to
a position such that the port b will be open to establish communication between the
steam-chest and the right-hand end of the cylinder, the inner and outer valve-sections
remaining in contact until the piston bas moved to the end of its stroke. By this
arrangement a complete exhaust is secured.
Heretofore in valves of the class to which this invention relates-that is, those
embodying an inner section, which controls the exhaust, and an outer section, which
controls the inlet, of the motive agent-considerable difficulty has been experienced,
owing to the liability of the valve to rise from its seat; but this difficulty I entirely
overcome by establishing a free communication between the under side of the central
portion of the top of the outer valve-section and the surrounding atmosphere by way
of the exhaust-ports through the inner valve-section. The inner valve section A is
firmly held to its seat by the pressure of the steam, which is free to enter the space
between the upper portion of the inner valve and the outer valve by way of the
apertures i.
As before stated, there are spaces between the outer end faces of the flange f and
the inner faces of the end flanges d, which spaces are shown best at o in Fig. 1. By
means of these spaces o a free communication about the outer faces of the flange fis
secured, the steam passing from the left of the inner valve-section to the right of the
said section as the outer valve section moves from the position in which it is shown in
Fig. 3 to the position in which it is shown in Fig. 4, whereby a cushioning of the
parts is secured and all undue shock or jar prevented, a similar cushioning being
secured between the upper bearing-faces of the two valve-sections by forming one or
both of such sections with cut away portions p, through which the steam passes as
the bearing-faces of the two valve sections approach.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is:
1st. A slide valve comprising an outer valve-section and an inner valve-section
having an open top, substantially as described.
2nd. A valve comprising an outer valve-section and an inner valve section having
an open top, and an upwardly extending flange that abuis against the under side of
the outer valve-section, substantially as described.
3rd. A valve comprising an outer valve-section formed with inwardly-extending
flanges and an inner-valve-section having an open top and a flange that abuts against

page_text: the under side of the outer valve-section, and an outwardly extending flange that is
overlapped by the inwardly extending flanges of the outer valve section, substantially
as described.
4th. A slide-valve comprising an outer valve-section operated by the valve-stem
and formed with corner apertures, and an inner valve section having an open top and
formed with a flange which abuts against the under side of the top of the outer valve-
section within the line of the corner apertures, substantially as described.
5th. A slide-valve comprising an outer valve section having a continuous bearing
face k, inwardly extending flanges e, and a flange d, and an inner valve-section
having an open top, an upwardly-extending flange which abuts against the under side
of the top of the outer valve section, and a surrounding flange f, that is overlapped by
the bearing-face k, and the inwardly-extending flanges of the outer valve section,
spaces o being left between the flanges f and d, substantially as described.
6th. A slide-valve comprising an outer valve section and an inner valve-section,
between which sections there is a chamber that is at all times in free communication
with the motive agent, substantially as described.
7th. A slide-valve comprising an outer valve-section actuated by the valve gear and
an inner valve section having an open top, whereby a portion of the top of the outer
valve-section will at all times register with the exhaust-port through the inner valve
section, substantially as described.
Dated this 21st day of June 1890.
F. W. BARKER,
Applicant's Agent.