IMPROVEMENTS IN SLIDE VALVES, WHICH IMPROVEMENTS ARE ALSO APPLICABLE TO OTHER RUBBING SURFACES
Year: 1874

page_text: LETTERS PATENT to John Henry Johnson, of 47, Lincolns Inn Fields,
in the County of Middlesex, Gentleman, for the Invention of
"IMPROVEMENTS IN SLIDE VALVES, WHICH IMPROVEMENTS ARE ALSO APPLICABLE
TO OTHER RUBBING SURFACES."-A communication from abroad by

page_text: executors, administrators, and assigns, Her Royal Letters Patent for
the same, and have made solemn Declaration that the said Invention
is communicated to me from abroad by Victor Forquenot, of Paris, in
the Republic of France.
NOW KNOW YE, that I, the said John Henry Johnson, do hereby.
declare that the following Complete Specification, under my hand and
scal, fully describes and ascertains the nature of the said Invention and
in what manner the same is to be performed in and by the following
statement, reference being had to the accompanying Drawings and to
the letters and figures marked thereon, that is to say :—
This Invention relates more particularly to slide valves, but is also
applicable to other rubbing surfaces where steam is employed, and has
for its object providing a more efficient means of lubrication, whereby
the friction and consequent wear of the surfaces in contact arc con-
siderably reduced.
It is well known that considerable inconvenience attends the use of
high-pressure steam in steam engines.
The slide valves and the valve faces especially are subjected to
abnormal wear by reason of the gripping or cutting of the surfaces in
contact, which wear is more or less rapid according to the nature and
hardness of the metals employed. This defect has hitherto been but
imperfectly remedied by the use of improved methods of lubrication,
and that only when the steam is not of a sufficiently elevated temperature
to affect the condition of the fatty matters employed. .
In locomotive, portable, and other steam engines the slide valves and
their faces become speedily worn by reason of the rapidity of the motion,
and the lateral portions which remain constantly in contact are par-
ticularly liable to the gripping or cutting action on account of their
non-lubrication.
This Invention consists in continuously interposing between the
rubbing surfaces either fatty bodies or steam, or water which the steam
conducts with it in impalpable droplets by means of small apertures or
cells disposed on the rubbing surfaces of the valve, which apertures or
cells receive or contain such steam, water, and oil during the working of
the engine. This arrangement admits of a high degree of polish in the
rubbing surfaces being obtained, whereby friction is diminished and the
abnormal wear of the parts is obviated.

page_text: of apertures or cells of suitable form and dimensions, and so arranged
as to fulfil the required conditions of lubrication, according to the par-
ticular circumstances of the case.
And in order that the said Invention may be fully understood, I.
shall now proceed more particularly to describe the same, and for that
purpose shall refer to the several Figures on the annexed. Sheet of
Drawings, the same letters of reference indicating corresponding parts
in all the Figures.
Figure 1 represents a plan; Figure 2, a longitudinal section; and
Figure 3, a transverse section of a slide valve for a steam engine con-
structed according to this Invention.
.
Figure 4 is a longitudinal section, and Figure 5, a transverse section
of the valve box or steam chest, showing the improved valves applied
thereto.
A is the slido valve and B the valve box or steam chest; a arc, the
apertures or cells, which are disposed on the slide valve, both on the
lateral supporting faces and on the faces which cover the ports. In
Figures 4 and 5 the valve is represented at one end of its stroke.
It will be seen on reference to Figure 4 that in this position of the
valve the rows or series of apertures or cells marked 1, 2, 4, and 6, will
be filled with steam, some from the admission side and the others from
the exhaust side, and that those marked 3 and 5 will also alternately be
brought into a position to receive a supply.
The apertures or cells on the lateral surfaces b, c, (Figure 1) will be
constantly filled either with the admission steam or the exhaust steam.
Similar arrangements may also be applied to slide and other valves of
every form and description for distributing steam, and whether such
steam be employed with or without condensation.
It is obvious that the apertures or cells may be arranged in various
ways, as for example, quincuncially or so as to "break joint" or other-
wise, and that their form may be modified and their number and size
varied according to circumstances.
Having now described and particularly ascertained the nature of the
said Invention, and the manner in which the same is or may be used or

page_text: carried into effect, I would observe in conclusion that what I consider
to be novel and original, and therefore claim as the Invention is,-
First. Forming the rubbing surfaces of slide valves or the valve
facing with apertures or cells for receiving or containing steam, water,
or oil for the purpose of reducing the friction of such surfaces, sub-
stantially as herein-before described and illustrated by the accompanying
Drawings.
Second. The application of apertures or cells for receiving or con-
taining lubricating material to rubbing surfaces generally where steam is
employed as and for the purposes herein-before described.
In witness whereof, I, the said John Henry Johnson, have to this
my Completo Specification set my hand and seal, the Second
day of November One thousand eight hundred and seventy-
four