Im- PROVEMENTS IN SLIDE VALVES
Year: 1869

page_text: LETTERS PATENT to Abraham Hemingway, of the City of Manchester,
in the County of Lancaster, Engineer, for the Invention of "Im-
PROVEMENTS IN SLIDE VALVES."
Sealed the 26th November 1869, and dated the 29th May 1869.
PROVISIONAL SPECIFICATION left by the said Abraham Hemingway
at the Office of the Commissioners of Patents, with his Petition, on
the 29th May 1869.
I, ABRAHAM HEMINGWAY, of the City of Manchester, in the County
of Lancaster, Engineer, do hereby declare the nature of the said Inven-
tion for "IMPROVEMENTS IN SLIDE VALVES," to be as follows:-
This Invention relates to slide valves for steam and water engines,
water pipes, and for all purposes where slide valves are used, and consists
in improved arrangements for enabling the slide to work easily when
acted upon by the pressure of steam and water. I form the back of the
slide open, and place in the interior a plate which rests on one or more
rockers linked or connected to the plate, which plate is kept tight by
means of a sheet of india-rubber, or a metallic spring, or other. well-

page_text: known means; or I employ a piston pressing on the rocker or rockers.
When there is only one rocker it works on the metal in the middle of
the ports, and when there are two they work on the metal at the sides
of the ports, and as the slide is moved to and fro the rockers rock on
the metal, and thus the friction is reduced to a very great extent, there
being only sufficient friction to keep the valve tight to its facing.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Abraham Hemingway in the Great Seal Patent
Office on the 29th November 1869.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ABRAHAM
HEMINGWAY, of the City of Manchester, in the County of Lancaster,
Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-ninth day of May, in the year
of our Lord One thousand eight hundred and sixty-nine, in the thirty-
second year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said Abraham Hemingway, Her special license
that I, the said Abraham Hemingway, my executors, administrators,
and assigns, or such others as I, the said Abraham Hemingway, my
exccutors, administrators, and assigns, should at any time agree with,
and no others, from time to time and at all times thereafter during
the term therein expressed, should and lawfully might make, use,
exercise, and vend, within the United Kingdom of Great Britain and
Ireland, the Channel Islands, and Isle of Man, an Invention for "IN-
PROVEMENTS IN SLIDE VALVES." upon the condition (amongst others) that
I, the said Abraham Hemingway, my executors or administrators, by an
instrument in writing under my, or their, or one of their hands and
seals, should particularly describe and ascertain the nature of the said
Invention, and in what manner the same was to be performed, and
cause the same to be filed in the Great Scal Patent Office within six
calendar months next and immediately after the date of the said Letters
Patent.

page_text: is to be performed, to be particularly described and ascertained in and
by the following statement (that is to say):-
This Invention relates to slide valves for steam and water engines,"
water pipes, and for all purposes where slide valves are used, and consists
in improved arrangements for enabling the valves to work easily when
acted upon by the pressure of steam or water. I form the back of the
valve open, and place in the interior a plate which rests on one or more
rockers linked or toothed to the plate, which plate is kept tight by a
sheet of india-rubber or a metallic packing. When there is only one
rocker it works on metal in the middle of the exhaust port or passage,
and as the valve is moved to and fro the rocker rocks on the metal, and
thus the friction is reduced to a very great extent, there being only
sufficient valve surface to keep the valve tight to its facing, and when
there are two rockers they work on metal at the ends of the exhaust port
or passage and support the plate pressed by the steam or water.
This Invention will be clearly understood by the following particular
description thereof, reference being had to the Figures and letters on
the accompanying two Sheets of Drawings, in which I represent the
application of my improvements to the slide valves of locomotive
engines, the valve shewn in the Figures on Sheet 1 being kept tight
by a sheet of india-rubber, and that in the Figures on Sheet 2 by a
metallic packing, and all the Figures are drawn about half size, and
similar letters refer to similar parts.
Fig. 1 on both Sheets is a transverse section of the steam chest and
valve provided with one of my improved rockers at the middle of the
exhaust port; Fig. 2, a plan of the valve facing covered by one-half of
the valve; and Fig. 3, a longitudinal section of the valve rocker and
facing.
In all the Figures the valve open at the back is marked a, and in the
opening is fitted the plate b, so that it can move up and down, and this
plate rests on the rocker c, d, which works on the bridge e fixed in the
exhaust port to the cylinder g by the screws h. At the bottom of the
rocker there are teeth i gearing into recesses in the bridge e, and at each.
upper end c of the rocker there is a tooth k gearing into recesses in the
plate b, which arrangement is for the purpose of keeping the rocker in
its proper position if the valve should be raised from its facing. To the
plate 6 are fixed brackets having open spaces m, through which the
upper ends of the rocker are passed for the purpose of keeping the

page_text: rocker to the plate if the valve should be lifted from its facing. The
plate b, Figs. 1 and 3, Sheet 1, is kept steam-tight by the india-rubber
sheet n, held in its place by the thin metallic plate o screwed to the
valve, there being holes p to prevent the steam from acting on the
plate o by admitting it to the surface of the india-rubber in contact with
the plate carried by the rocker c, d. The plate 6, Figs. 1, 2, and 3,
Sheet 2, is kept steam-tight by the metallic packing 9 placed in a groove
formed in all the sides of the plate, as shewn in Figs. 1 and 3, and in
the plate above the packing there are small holes r, Figs. 1 and 2, for
admitting steam to press the packing against the interior of the valve,
and keep the parts tight. When the steam is let into the steam chest it
acts directly on the plate b, Figs. 1, 2, and 3, Sheet 2, or it passes
through the holes p, Figs. 1, 2, and 3, Sheet 1, to the surface of the
india-rubber, and exerts its force on the plate b, and therefore in both
cases it is only the surface of the valve outside the plate & that is exposed
to the pressure of the steam, and as the rocker when supporting the
great pressure on the plate b rocks on the bridge the valve can be easily
moved to and fro. The valves shewn in the Drawings are of much
greater width than length, but for other descriptions of steam engines,
water engines, water pipes, and other apparatus, the valves are made
of the various shapes required, and kept tight as before described, or by
pistons or other well-known means.
Having now described the nature and particulars of my said Inven-
tion and the manner in which the same is to be performed, I desire it to
be understood that I claim, the application to slide valves of one or
more rockers for enabling the valves to be worked easily when acted
upon by the pressure of steam or water, as herein described and
illustrated on the accompanying two Sheets of Drawings.
In witness whereof, I, the said Abraham Hemingway, have here-
unto set my hand and seal, this Fifteenth day of October, in the
year of our Lord One thousand eight hundred and sixty-nine.